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Inorganic chemicals News

Barium hydroxide emergency methods

Spill response
Isolation leakage polluted area, restricting access. Recommended emergency personnel wearing self-contained breathing apparatus to wear protective clothing. Do not direct contact with leakage. A small leak: to avoid dust, with clean shovel collection in a dry, clean, covered containers. Large leak: covered with plastic sheeting, canvas, reduce dispersion. Then the collection, recycling or shipped to the waste disposal sites.
Protective measures
Respiratory protection: its possible exposure to dust, must wear headgear electric powered air purifying respirators and dust. Emergency rescue or evacuation, it is recommended to wear air respirators.
Eye protection: Respiratory Protection has been protective.
Physical protection: wear rubber acid suit.
Hand Protection: Wear rubber gloves acid.
Other: work site prohibit smoking, eating and drinking. Work to complete, take a shower. Separate storage of toxic pollution by the clothes, washed standby. Maintain good health habits.
First aid measures
Skin contact: Remove contaminated clothing, use soap and water thoroughly washed skin.
Eye contact: Did eyelid, mobile water or saline. Doctor.
Inhalation: rapidly from the scene to fresh air. Keep the airway patency. If breathing is difficult, give oxygen. If not breathing, give artificial respiration immediately. Doctor.
Ingestion: drink plenty of water, induce vomiting, with 2% to 5% sodium sulfate solution lavage, catharsis. Doctor.
Fire fighting methods: This product is non-combustible. Extinguishing Media: Water, sand.

Ammonium persulfate main purpose

Verification and determination of manganese, used as the oxidant. Bleach. Photographic reductant and blockers. Battery depolarizer. For the preparation of soluble starch.
Vinyl monomers as vinyl acetate, acrylate emulsion polymerization initiator, cheap, good water resistance of the resulting emulsion. Urea-formaldehyde resins are also used as a curing agent, curing fastest. Starch is also used as a co-oxidant adhesive, the starch component of the reaction and improve the adhesion protein, the reference amount of 0.2% to 0.4% starch. Copper is also used as a surface treatment agent.
Chemical Industry persulfate and hydrogen peroxide used in the manufacture of raw materials, to help organic polymer polyethylene polymerization agent, the initiator of polymerization of vinyl chloride monomer. Grease, soap industry as a bleaching agent. Also used in the oil industry and oil and other corrosive metal plate corrosion when cutting aspects. Food-grade wheat used modifier, brewer’s yeast mildew

Ammonium bicarbonate production methods

1 through the compressed carbon dioxide into the concentrated aqueous ammonia, carbon dioxide and placed under pressure, and cooled, precipitated crystals were separated by centrifugation, from dehydration. When purification was dissolved in water, ethanol was added, so that recrystallization.
(2) After carbonization absorbing ammonia water, carbonation with carbon dioxide, and then separated and dried to obtain ammonium bicarbonate. The chemical reaction equation:
NH3 + CO2 + H2O → NH4HCO3
3 from lime and washed purified CO2 gas, which leads to ammonia to make it saturated after separation by centrifugation, hot air drying derived products. [4]
4 Typical small nitrogenous fertilizer plant to produce ammonium bicarbonate anthracite as raw material, preparation of semi-water gas, which after removal of hydrogen sulfide into the pressurized shift reaction system, resulting nitrogen, hydrogen and carbon dioxide mixture into the carbonation tower, In this concentration of carbon dioxide and about 17% aqueous ammonia, ammonium bicarbonate crystals separated by a centrifuge to obtain ammonium bicarbonate products. Removal of carbon dioxide feed gas, after further removal of a small amount of residual carbon dioxide and carbon monoxide into the ammonia synthesis systems. Dried at room temperature, ammonium bicarbonate, a certain stability and good flowability. Some Chinese bicarbonate plant using air-drying method to product drying; adding more plants using crystallization modifiers way to make ammonium bicarbonate crystals grow relatively thick, solid liquid separation so as to improve the operating conditions, so from 5% moisture content of product ~ 5.5% decrease 3.5% to 2.5%, and reducing the loss of decomposition products of the agglomeration have a significant effect. [3]
Production of ammonium bicarbonate reaction is:
NH3 + H2O → NH3 * H2O + heat NH3 · H2O + CO2 → NH4HCO3 + heat.

Magnesium sulfate main purpose

Medicine
( 1 ) magnesium inhibit the central nervous system , skeletal muscle relaxation , a sedative , antispasmodic and reduce intracranial pressure and so on. Commonly used to treat seizures, eclampsia, uremia , such as tetanus and hypertensive encephalopathy . More in 10 ml of 10% magnesium deep intramuscular or diluted with 5 % glucose 2% to 2.5% of a solution of the slow drip . It should be noted direct intravenous or intramuscular injection of large doses of magnesium is very dangerous , usually a maximum of 25% magnesium sulfate with 15 ml can. Should be used to observe the patient’s breathing and blood pressure , slow knee reflex is an important sign of a sufficient amount of magnesium ions .
( 2 ) Magnesium has an extremely important role in the metabolism of sugar and a protein . Child growth and development period of time if there is indigestion and vitamin D, magnesium salt should be added .
( 3 ) having a plurality of magnesium potassium similar physiological functions. Due to the lack of clinical manifestations of magnesium and potassium similar, so magnesium deficiency is often easily overlooked. When potassium and when potassium after no improvement of symptoms , you should first take into account the possibility of magnesium deficiency , so in order to make timely corrective hypomagnesemia . Thus , long-term infusion of the patient , at the same time pay attention to the potassium magnesium supplementation . Plus 1 g daily infusion of magnesium sulfate to prevent the occurrence of hypomagnesemia .
( 4 ) patients with cardiac dysfunction when using digitalis drugs may be appropriate to supplement magnesium, low magnesium aggravated prevent digitalis toxicity . Treatment with magnesium tachycardia often effective clinically .
( 5 ) Oral magnesium little absorption in the intestine , so none of the above purposes. But there is good oral magnesium sulfate catharsis function, so called magnesium sulfate Epsom salts . Reaches the intestine after oral administration of aqueous magnesium sulfate solution , a certain osmotic pressure, so that water is not absorbed by the intestinal wall . Enteral retain large amounts of water , able to stimulate intestinal peristalsis and defecation. Thus magnesium sulfate for the treatment of constipation, intestinal abnormal fermentation ; with insect repellent and use, intestinal worms can easily eliminated . Can each be 5 to 20 grams of magnesium sulfate dissolved in 100 to 400 ml of warm water in the morning orally once . High concentration difficult , preferably 5% , otherwise the delay defecation .
( 6 ) magnesium can stimulate the duodenal mucosa , bile duct caused by reflex sphincter relaxation , cholecystokinin , thereby promoting gallbladder emptying, choleretic effect. For the treatment of cholecystitis and cholelithiasis , each 2 to 5 grams , 3- times daily, before meals or food orally. 50% to 33% of magnesium sulfate dilution (high concentration ), 5ml Tid.
( 7 ) magnesium sulfate can be used as gastrointestinal contrast
( 8 ) anti-inflammatory to the swelling of the goods 50% topical solution heat affected area , remove swelling anti-inflammatory effect.
Topical magnesium powder can be swelling, swelling after treatment for physical trauma, to help improve rough skin and so on.
Magnesium

Magnesium
magnesium sulfate soluble in water, not orally absorbed, aqueous solution of magnesium ions and sulfate ions are not easily absorbed by the intestinal wall , so that intestinal osmotic pressure, the water body fluids move to the intestine , so that the intestine volume increase , wall expansion , thereby stimulating intestinal afferent nerve endings caused by reflex increases peristalsis catharsis , its role in the entire bowel , so fast and strong . As a cathartic agent and duodenal drainage agent.
Intravenous and intramuscular magnesium sulfate is mainly used anticonvulsant, it can cause blood vessels to dilate , causing blood pressure to drop , due to the central inhibition and skeletal muscle relaxant effect of magnesium sulfate , antihypertensive effect, mainly used in clinical remission eclampsia, tetanus such as seizures , but also for the treatment of hypertensive crisis . Also used as a drug solution of barium salts.
Industry
For tanning , explosives , fertilizers , paper , porcelain, printing dyes, lead-acid battery industry. Magnesium and other potassium , calcium, amino acid salts , minerals such as silicates , bath salts can be used .
Agriculture
Fertilizer: In agriculture and gardening , magnesium sulfate is used to improve soil magnesium (magnesium is an essential element of the chlorophyll molecule ) , the most commonly used for potted plants , or magnesium crops, such as potatoes, roses, tomatoes, peppers and marijuana. Administration of magnesium sulfate advantage over other magnesium magnesium soil amendments ( such as dolomitic lime ) is its high solubility.
Feed: feed grade magnesium as magnesium supplement feed processing . Magnesium is involved in osteoblast animal body and muscle contraction process indispensable factor is the animal in vivo activator of many enzymes , the body of the animal ‘s metabolism and nerve function plays an extremely important role. If the animal body magnesium deficiency , metabolism and can cause neurological disorders, feeding disorders, affect animal growth and development, and even lead to death

The main purpose of Sodium sulfite anhydrous

1 , the chemical industry for the manufacture of sodium sulfide sodium silicate and other chemical products .
2, the paper industry for the manufacture of kraft pulp cooking when agents .
3 , made ​​of soda glass industry to replace the co- solvent.
4 , the textile industry for the deployment of Vinylon spinning coagulant.
5, for the non-ferrous metallurgy , leather and so on.
6 ,Sodium sulfite anhydrous  used for making sodium sulfide , pulp , glass, water glass , enamel , also used as laxatives and barium salt poisoning antidotes . Is a byproduct of the manufacture of hydrochloric acid and sulfuric acid with salt when . For the manufacture of sodium sulfide , sodium silicate on the chemical . Laboratory for wash barium salt . Preparation for the industry to take NaOH and H ₂ SO ₄ raw materials , but also for paper, glass , printing and dyeing , synthetic fiber , leather and so on. Sodium in an organic synthesis laboratory of the most commonly used treatment desiccant.
7 Sodium sulfite anhydrous mainly used as synthetic detergent filler. Paper industry for cooking agent when manufacturing kraft pulp . Glass industry to replace soda . The chemical industry for the manufacture of sodium sulfide , sodium silicate raw materials and other chemical products . The textile industry for the deployment of Vinylon coagulating bath . The pharmaceutical industry as laxatives . Also used in non-ferrous metallurgy , leather and so on.
8 , so that the hydration products sulphoaluminate generate faster , thereby speeding up the rate of cement hydration and hardening . Sodium content of cement quality is generally 0.5 % to 2% , can improve the early strength of concrete by 50% to 100%, 28 days to improve the strength and sometimes , sometimes lower , increase rate of about 10% , with the type of cement , curing conditions its content varies . Also used as synthetic detergent filler , but also for the paper industry , glass industry, chemical industry, textile industry and pharmaceutical industry.
9 , Sodium sulfite anhydrous used as analytical reagents, such as dehydration, digestive catalyst fixed nitrogen , atomic absorption spectroscopy interference inhibitors. Also used in the pharmaceutical industry .
10 , for the chemical, paper and glass , dyes, printing and pharmaceutical industry, in the manufacture of synthetic fibers , leather , non-ferrous metallurgy , enamel , etc. There are also applications , also used as an additive in detergents and soaps .
11 , Sodium sulfite anhydrous can be used as a buffer to stabilize the sulfate zinc ph value of the bath .

soda ash production methods

Development History
4.1.1 soda ash Laboratory Methods
Laboratory Preparation of sodium carbonate :
.
4.1.2 soda ash Lv Bulan Law
First in 1791 , the ancients began with salt , sulfuric acid, coal, limestone as raw material to produce sodium carbonate , is Lv Bulan method.
This method does not fully utilize the raw material , poor working conditions, poor product quality , and gradually replaced by Solvay process .
4.1.3 soda ash Solvay process
1859 , Belgian Solvay , with salt , ammonia , carbon dioxide as raw materials, at room temperature to precipitate sodium bicarbonate from the solution, heating it, and that the decomposition of sodium carbonate , alkali people this method is known as the Soxhlet this method has been in use ever since.
4.1.4 soda ash Houde Bang Law
1943 Chinese people studying abroad returned Houde Bang , he combined Mainland China ‘s national conditions and lack of salt on the Solvay process improvements , the two industrial joint soda ash and ammonia , while the production of sodium carbonate and ammonium chloride fertilizer , greatly improved salt utilization, is Hou soda method.
Reaction principle
Soxhlet soda method and the main chemical reaction Hou soda method are :
Reaction one :
NaHCO3 ( sodium bicarbonate ) soluble only under these conditions , greater than the solubility of sodium bicarbonate dissolved under this condition , the precipitated solid sodium bicarbonate , filtered to afford solid sodium bicarbonate .
Reaction II:
Hou alkali and alkali Soxhlet method different method is the preparation of the Soxhlet process is recycled NH3 :
And Hou law throughout the preparation process , NH4Cl directly as a byproduct of soda ash —- fertilizer.
So Soxhlet products are sodium carbonate, calcium chloride byproduct ; while Hou law product is sodium carbonate, ammonium chloride byproduct .
Hou alkali method
Namely:
① NaCl ( saturated ) + NH3 + H2O + CO2 ==== NH4Cl + NaHCO3

Ammonia and carbon dioxide reacts with the water molecule of ammonium bicarbonate , which is the first step .
( 1 )
The second step : the reaction of sodium bicarbonate and precipitates of sodium bicarbonate and ammonium chloride , sodium bicarbonate and the reason is because precipitation of the less soluble .
(2) NH ₄ HCO ₃ + NaCl ( saturated ) ==== NH ₄ Cl + NaHCO ₃ ↓
Part can be directly synthesized sodium bicarbonate factory sales , and the rest will be thermal decomposition of sodium bicarbonate to produce sodium carbonate, carbon dioxide can be generated back to the first step !
( 3 )
According NH4Cl solubility than NaCl, at a low temperature than the solubility of NaCl principle , 278K ~ 283K (5 ℃ ~ 10 ℃) when , salt powder was added to the mother liquor , leaving to crystallize for doing NH4Cl nitrogen alone .
Advantages of this method : the ammonia soda process retains the advantages , it eliminates the drawbacks that increase the utilization of salt to 96%; NH4Cl do nitrogen ; ammonia plant with a joint , so that the ammonia feed gas CO into CO2, leather In addition to this process CO2 CaCO3 system .

The main purpose of manganese sulfate

Mineral industry for the production and preparation of various manganese and manganese salts. Coatings industry for the production of driers and linoleic acid and manganese , metal products phosphating agent . Cable is an important trace element fertilizers in agriculture , but also plant chlorophyll synthesis catalyst . Impose an appropriate amount of manganese sulfate solution , can grow well in a variety of crops , increase production.
Expected effects of manganese sulfate dressing : dressing with manganese sulfate solution can increase grain weight , yield 10% to 15 %.
Dressing method : before planting the first 0.2 kg manganese sulfate dissolved in 0.9 kg of water , and then mixed with 50 kg of wheat seed .
Important micronutrient fertilizer, can be used as base fertilizer , seed soaking , seed dressing , dressing and foliar spraying , can promote the growth of crops to increase production. In animal husbandry and feed industry, as feed additives, can make the animal well-developed , and fattening effect. Also processing paint , ink driers ; raw tea manganese solution ; used as a catalyst for synthesis of fatty acids ; addition, also used in paper , ceramics, printing and dyeing , ore flotation ; manganese production of raw materials and the manufacture of other raw manganese salt . Also used in batteries, smelting catalyst , analytical reagents , mordant , additives , pharmaceutical excipients .
Mainly in the pituitary , pancreas, liver and bone mitochondria as an integral part of many enzymes . Manganese involved in hematopoiesis in vivo , to promote the oxidation of fat cells , prevents atherosclerosis . Manganese deficiency can cause growth retardation , osteoporosis and exercise disorders.
Is one of the important micronutrient fertilizer, can be used as base fertilizer , seed soaking , seed dressing , dressing and foliar spraying , can promote the growth of crops to increase production. In animal husbandry and feed industry, as feed additives, can make the animal well-developed , and fattening effect. Also processing paint , ink driers ; raw tea manganese solution ; used as a catalyst for synthesis of fatty acids ; addition, also used in paper , ceramics, printing and dyeing , ore flotation ; manganese production of raw materials and the manufacture of other raw manganese salt . Also used in batteries, smelting catalyst , analytical reagents , mordant , additives , pharmaceutical excipients

Potassium sorbate

1 Introduction
Generic hexadiene – ( 2,4 ) – potassium ; 2,4 – potassium sorbate
Formula C6H7KO2
Simple structure CH3CH = CHCH = CHCOOK
Quality standard: National People’s Republic of China GB13736-2008
Commonly known as: Preservatives
ChI = 1/C6H8O2.K/c1-2-3-4-5-6 (7) 8 ;/ h2-5H, 1H3, (H, 7,8) ;/ q; +1 / p-1/b3 -2 +,5 -4 + ;
2 production methods
1 and mainly uses the method. Sorbic acid as raw materials, potassium hydroxide or potassium carbonate for neutralization reaction.
2 sorbic acid was added to the reaction kettle , sorbic acid was then added to 66% by mass of water, was added dropwise a solution of 49% potassium hydroxide at 45 ℃, Ph = 8 until the reaction solution until the reaction is about 45min. Adding a certain amount of carbon, vacuum filtration , at 40 ~ 45 ℃ and the filtrate was evaporated under reduced pressure reaches 3 ~ 4h after heating to 70 ℃ discharge requirements . By centrifugal dehydration crystallization liquor recovery ; finally dried to obtain the product under 105 ℃. [ 1 ]
3 Uses
The main use
Preservatives for food preservatives are acidic reaction with organic acids using antiseptic effect increased . Potassium carbonate or potassium hydroxide and sorbic acid as raw materials. [ 2 ]
Sorbic acid ( potassium ) can effectively inhibit mold , yeast and the activity of aerobic bacteria , so as to effectively extend the storage time of the food and keep the original flavor of the food .
We buy the packaging ( or canned ) food , the ingredients often see one of the words ” sorbic acid ” or ” potassium sorbate ” , people often mistakenly thought to be components of the fruit , ” pear” is . In fact, they are commonly used in food additives ! Whether they have no harm to human body , plain consumption is indeed necessary , the following is the relevant information about the sorbic acid , potassium sorbate for reference only:
Sorbic acid ( chemical name : 2,4 – sorbic acid Formula : C6H8O2 ]
Potassium sorbate ( chemical name : 2,4 – potassium sorbate ] Formula : C6H7KO2)
Sorbic acid, potassium sorbate properties, uses similar : Sorbic acid is recommended by the FAO and WHO efficient and safe preservative widely used in food , beverages, tobacco , pesticides, cosmetics and other industries , as the unsaturated acid, also can be used in resins, spices and rubber industry.
4 Nature
Physical Properties
Potassium sorbate is a white to pale yellow crystalline flake , crystalline granule or crystalline powder , odorless or slight odor, hygroscopic long-term exposure to air, oxidation and decomposition and discoloration. Soluble in water , potassium sorbate , 67.6g/100ml (20 ℃); 5% brine , 47.5g/100ml ( room temperature ) ; 25% sugar , 51g/100ml ( room temperature ) . Dissolved in propylene glycol , 5.8g/100ml; ethanol , 0.3g/100ml. 1% aqueous solution of potassium sorbate PH7 ~ 8.
Spectral characteristics
Using FLS 920 fluorescence spectrometer to study the three-dimensional fluorescence spectra of potassium sorbate solution was found when moved from 320 nm excitation light red 500 nm, fluorescence has two peaks : 485 nm and 565 nm, the former strength significantly greater than the latter , the corresponding the excitation peak was 380 nm and 470 nm.
Fluorescence analysis of these two peaks is potassium sorbate molecule conjugated π bond and non-bonding electron stimulated transitions caused by n , in accordance with its peak at 485 nm the fluorescence intensity with the concentration of (0.05 ~ 12 g / L ) non-linear variation of the concentration of potassium sorbate can be detected . further to fresh apple juice , for example, based on fluorescence spectroscopy to study the feasibility of potassium sorbate was detected in fresh apple juice mass concentration . [ 3 ]
Chemical properties
Combustible , fire exhaust fumes containing potassium spicy . Has a strong inhibitory effect of spoilage bacteria and fungi , and because of the low toxicity than other preservatives , it has become the world ‘s leading preservatives. Under acidic conditions, corrosion can give full play the role of a neutral role when low.
Cosmetic preservatives. An organic acid preservatives. Average amount of 0.5 %. May be mixed with sorbic acid . Although potassium sorbate soluble in water, easy to use, but its pH 1% solution is 7-8 , so there is a tendency to increase the pH of cosmetics , should be taken when using .
Content analysis:
After taking pre- dried sample 0.25g 105 ℃ 3h after ( accurate to 0.1mg). Add 250ml flask with a glass stopper , add 36ml of glacial acetic acid and acetic anhydride 4m1, warm make into a solution . Cooled to room temperature , add crystal violet test solution (TS-74) 2 drops of 0.1mol / L acetic acid solution through the blue-green endpoint titration to acid and to maintain 30s does not disappear. Meanwhile blank test , and make the necessary corrections. Each Ml0.1mol / L perchloric acid is equivalent potassium sorbate (C6H7KO2) 15.02mg.
Toxicity: Continue reading

Sodium thiosulfate

1 Physical and Chemical Properties
Physical Properties: colorless transparent sodium thiosulfate

Monoclinic crystals , soluble in water , insoluble in alcohol . Pentahydrate temperature 48 degrees Celsius, the melt in the melting of crystal water .
Chemical properties: heat decomposition, decomposed into sodium and sulfur or sodium sulfate and sodium polysulfide , while being oxidized by oxygen . In case of acid decomposition of sodium thiosulfate emit sulfur dioxide gas and sulfur precipitation . Heating in air oxidation and decomposition into sodium , sulfur dioxide and water. Combustion generated sulfate, sodium sulfide and sulfur in the absence of air .
2 Determination
Method name: Sodium thiosulfate – Determination of sodium thiosulfate – Redox Titration
Application: This method uses sodium thiosulfate determination of redox titration. This method applies to the determination of sodium thiosulfate .
Method: Take the test amount , add water to dissolve , add starch indicator solution with iodine solution was titrated droplet to continuous blue. Each 1mL iodine titration solution (0.05mol / L) is equivalent to 15.81mg of Na2S2O3. Computing , that is.
Reagents:
1 water ( boiling placed to room temperature )
2 . Iodine titration solution (0.05mol / L)
3 sodium hydroxide solution (1mol / L)
4 methyl orange indicator solution
5 . Sulfuric acid titration solution (0.5mol / L)
6. Sodium bicarbonate
7 starch indicator solution
8 phenolphthalein indicator solution
9 methyl red – bromocresol green mixed indicator solution
10 benchmark arsenic trioxide
11 Basis of potassium hydrogen phthalate
12 benchmark anhydrous sodium carbonate
3 Uses Introduction
When tanning dichromate reducing agent , nitrogen exhaust neutralizer , mordant , straw and
Hair bleach and bleach pulp dechlorination time . Also for tetraethyl lead , dyes intermediates manufacturing and ore mention silver electroplating industry reductant , water purifying agent works .
In the textile industry for bleaching cotton after dechlorination agent , sulfur dyeing wool fabric dye , indigo dye anti- white agents , pulp dechlorination agent , the pharmaceutical industry as detergents, disinfectants and bleaching agents. [ 1 ] analysis reagents for chromatography reagents , drip Determination of cobalt , photographic fixer , dechlorination agent capacity analysis commonly used reagents, sodium, preparation of injectables and double sugar iron urea medium mordant .
Thiosulfate cyanide can also be used as antidotes .
4 Method
Commonly used industrial sulfur with sodium sulfite and sodium thiosulfate to give boiled , purified by recrystallization : Na2SO3 + S + 5H2O = Na2S2O3 · 5H2O
Sodium sulfite dissolved soda method , and ( combustion of sulfur ) of sulfur dioxide and generated sodium sulfite , sulfur boiling reactor was added , filtered , concentrated and crystallized to obtain sodium thiosulfate .

Na2CO3 + SO2 == Na2SO3 + CO2
Na2SO3 + S +5 H2O == Na2S2O3.5H2O
Evaporation residue method using sodium sulfide , sodium sulfide , sodium carbonate and sodium sulfide sulfur dioxide react with barium sulfide in wastewater emissions of sulfur by sulfur absorption , evaporation, crystallization , obtained sodium thiosulfate .
2Na2S + Na2CO3 +4 SO2 == 3Na2S2O3 + CO2
Oxide , sodium sulfite , and the recrystallization containing sodium sulfide, sodium sulfite and caustic soda liquid sulfur by oxidation ; sodium bisulfite and sulfur crude product by recrystallization three thiosulfate thiosulfate resulting mixture was concentrated , crystallized to obtain sodium thiosulfate .
2Na2S +2 S +3 O2 == 2Na2S2O3
Na2SO3 + S == Na2S2O3
Recrystallization of the crude crystals were dissolved sodium thiosulfate (or the crude solution of sodium thiosulfate ) , after cleaning, concentrated and crystallized to obtain sodium thiosulfate .
5 Considerations
Should be stored in a cool dry place . Transportation should avoid exposure to rain. Not with acids , oxidizers of storage or shipment . Containers must be sealed to prevent moisture dissolves. Such as packaging damp, description of contents has played the role of deliquescence , must be packaged dry stacked separately. Can not be stored in the open air, to seize on the damp package deal . When fighting fire with water sand .
It can be the solution of cyanide poisoning and mercuric chloride poisoning
Acute cyanide poisoning rapid progression of the disease , it should be against the clock to rescue acute poisoning , emphasizing locally applied antidote.
1 , oral poisoning , gastric lavage available 1:2000 potassium permanganate solution and vomiting induced by stimulation of the posterior pharyngeal lavage ;
2 , inhalation poisoning should be immediately evacuated , move to fresh air , well-ventilated place to rest ;
3, with sub- acid amyl nitrate after the crushing 1-2 branched into a handkerchief , nose and mouth before poisoning on inhalation, every two minutes , once every 5-6 times ;
4 , symptomatic treatment. Occur circulation , respiratory failure were given in the arm, vasopressors , respiratory stimulants, oxygen, artificial respiration ; skin burns , potassium permanganate solution, rinse , and then washed with ammonium sulfide solution ;
5 , after the above scene by emergency should be immediately sent to hospital for treatment , must not be delayed.
Nitrite – sodium thiosulfate therapy :
Detoxification mechanisms:
Methemoglobin formation agent such as nitrite can rapidly form of hemoglobin to methemoglobin , which ferric ions and free the body or in combination with cytochrome oxidase cyano combine to form an unstable cyanmethemoglobin , leaving ELISA inhibition . Cyanmethemoglobin in a few minutes can be dissociated cyanide ions , so the need to provide for rapid sulfur agents such as sodium thiosulfate , cyanide ions into the low toxicity of thiocyanate and excreted.
Usage:
Now amyl nitrite having 1 to 2 (0.2 ~ 0.4ml) wrapped in a clean cloth crushed to give 15 to 30 seconds inhalation , can be repeated after 5 minutes , a total of not more than 3 . Children each dose is 1 . After the formation of the pharmaceutical in the body is only a small amount of denatured hemoglobin, it is only as an emergency measure.
3% Sodium nitrite 10 ~ 15ml intravenous injection 2 ~ 3ml per minute. Children give 6 ~ 10mg/kg. These two drugs can lower blood pressure , a circulation disorder with caution .
At the same speed with the same injection needle 25 to 50% sodium thiosulfate 20 ~ 50ml. Children give 0.25 ~ 0.5g/kg. Repeat as necessary after an hour and a half or full amount of the amount of discretion after repeated use . Mild poisoning can be alone with this drug .
Soda is the colorless transparent crystal , easily soluble in water , aqueous solution is alkaline. It weathered the loss of crystal water above 33 ℃ in dry air. Neutral , alkaline solution is stable in the acidic solution will rapidly decompose .
Na2S2O3 +2 HCl = 2NaCl + H2O + S ↓ + SO2 ↑
Soda has a strong complexing ability trophies silver bromide to form complexes . Reaction formula : AgBr +2 Na2S2O3 = NaBr + Na3 [Ag (S2O3) 2], according to this property, it can be used as a fixing agent. Wash phase , with an excess of soda unexposed silver bromide on the film part of the reaction , the conversion of soluble Na3 [Ag (S2O3) 2], the removal of AgBr , the developing part fixed.
Soda also has a strong reduction, chlorine and other substances can be restored.
Na2S2O3 +4 Cl2 +5 H2O = 2H2SO4 +2 NaCl +6 HCl
Therefore, it can be used as a bleaching cotton fabric after dechlorination agent. Similar reasoning , the iodine stains on the fabric can also be used to remove it .
In addition, the soda is also used in leather tanning , electroplating and silver extracted from the ore .
Sweat stain ( tinea versicolor ) radical approach : topical 20% to 30 % sodium thiosulfate solution , topical 1% dilute hydrochloric acid immediately after dry ; or optional 3% Triatop lotion wash the affected area ; usage are daily from 1 to 2 times.
Packing: PVC bag or plastic lined woven bag , net weight 40 kg .

Storage: Store in a cool dry place . Dark, sealed storage, transport should avoid exposure to moisture and rain.

Silica gel

In general, the silicone can be divided according to their nature and composition of organic and inorganic silicone silicone two categories. Shape into its component silicone extrusion and molded silicone .
Inorganic silica is a highly active adsorption material , usually with sodium silicate and sulfuric acid , and after a series of aging process , acid bulbs , etc.

Obtained. An amorphous silica material , its chemical formula is mSiO2. nH2O. Insoluble in water and any solvent , non-toxic , odorless , chemically stable, does not react with any substance except alkali, hydrofluoric acid . Various types of silica are formed in different manufacturing methods of different pore structure . Chemical composition and physical structure of silica gel , and determines that it has many other similar materials difficult to replace characteristics: high adsorption properties, good thermal stability, chemical stability, high mechanical strength.
Silicone is an organosilicon compound containing a Si-C bond means , and at least one organic group is directly bonded to silicon atoms compound , and those on the regular habits through an oxygen , sulfur, and nitrogen, the organic silicon group compound atom is attached as an organic silicon compound . Among them, the silicon- oxygen bond (-Si-O-Si-) for the skeleton consisting of silicones, silicone compounds are the most numerous , most studies , the most widely used class of more than 90% of the total amount .
Extruded silicone relatively common , such as household electric cooker ring , called the rice cooker silicone seals .
Molded silicone bit more complicated , irregular shape, including silicone bowls, silicone ice tray , silicone bakeware and more.
Inorganic silicone
About inorganic silicone
Name: Silicone
Alias: silica gel or silicic acid gel
Name : Silica gel; Silica
MF : xSiO2 · yH2O
Weight: 60.08
CAS Registry Number : CAS # 112926-00-8
EINECS No. :231 -545-4
Word explanation : Chemical Formula xSio 2 · yH2O. Transparent or white granular solid . Has an open porous structure , strong adsorption, can absorb a variety of substances. Dilute sulfuric acid ( or hydrochloric acid ) in an aqueous solution of sodium silicate and allowed to stand , it will become hydrous silicate gel and solid-state technology . Washed with water electrolyte dissolved therein remove Na + and SO4 2 – (Cl-) ions, a silica gel can be dried . As absorb moisture , moisture is about 40% . For gas drying , gas absorption, liquid dewatering , color layer , but also used as catalysts. Such as cobalt chloride , dry blue, and red absorption . Repeated use of renewable .
Safety performance
The main ingredient is silica, silica gel , chemically stable , does not burn . Silica gel is an amorphous silica dust content of the workshop should be controlled less than 10 mg / cubic meter, the need to enhance ventilation, wear a mask when operating .
Silicone has a strong adsorption capacity, can produce human skin drying effect , therefore , the operation should wear good clothes. If the silicone into the eyes , flush with lots of water and seek medical treatment as soon as possible .
Blue silicone because it contains small amounts of cobalt chloride , toxic, should avoid contact and inhalation of the mouth and food , such as the occurrence of poisoning should immediately seek medical treatment.
Silica in the course of the medium due to the adsorption of water vapor or other organic substances , the adsorption capacity decreased after regeneration can be reused.
Security terms :. S22 Do not breathe dust Do not breathe dust.
Silicone regeneration
A reproduction after absorbing silica
Silica gel adsorption of water , thermal desorption way through the water to remove heat in different ways , such as electric heaters , heating and hot flue heat drying . Desorption temperature control in heating 120 – 180 ℃ is appropriate, for the blue gel indicator , color gel , DL -type blue silicone control at 100 – 120 ℃ appropriate. The maximum temperature of various industrial silicone regeneration should not exceed the following limits :
Coarse pore silica shall not exceed 600 ℃;
Pore ​​silica shall not exceed 200 ℃;
Blue plastic indicator agent ( or color gel ) shall not exceed 120 ℃;
Silica-alumina gel shall not exceed 350 ℃.
Silicone regeneration , the general control 2% moisture or less back into use .
Renewable two , silica gel adsorption of organic impurities
⒈ roasting method
For coarse -pored silica gel , gradually warming up to 500 can be placed within the roaster – 600 ℃, after about 6-8 hours to

Particles can be white or brown . Of silica gel pores , the firing temperature should not exceed 200 ℃.
⒉ rinsing method
After the silica gel in the saturated water vapor adsorption heat saturated water immersion rinsing detergent to remove oils or other organic impurities can be combined , dried and then dehydrated by washing water .
⒊ solvent flushing method
According to silica gel adsorption of organic species , the choice of an appropriate solvent adsorbed organic matter dissolved in the silica , silica gel is then heated to remove the solvent .
Third, the silicone should pay attention to the problem of regeneration
⒈ drying regeneration should be careful to gradually raise the temperature , so as not to cause severe drying particles burst, lower recoveries .
⒉ silicone baking for regeneration when the temperature is too high will cause changes in the pore structure of silica gel adsorption effect of significantly reducing the impact value. For blue or discoloration silica gel indicator , desorption regeneration temperature should not exceed 120 ℃, otherwise they will be gradually oxidized color developing agent and lose color effect.
⒊ regenerated by silica gel should generally screened to remove fine particles, so the particles evenly.
Storage and Packaging
Silicone has a strong capacity to absorb moisture and should therefore be stored in a dry place , packaging, between the ground and have a shelf . There packaging drums , drum , cardboard boxes, plastic bottles, polyethylene plastic bags, flexible container bags and so on. During transportation to avoid rain, moisture and sunlight .
The use of inorganic silica
Wide pore silica is generally used as a catalyst carrier, a matting agent , abrasive toothpaste . Therefore, different varieties should be selected depending on the purpose.
Silica gel desiccant can be used for , and can be reused. Silica is silica gel mSiO2 · nH2O made ​​suitable dehydrating porous materials of different particle sizes . An open porous structure having a specific surface area ( surface area per unit mass ) is large , many substances can be adsorbed , is a good desiccant, an adsorbent and a catalyst carrier. Silica gel adsorption is mainly physical adsorption, can be regenerated and used repeatedly. Adding an acid to an alkali metal silicate ( such as sodium ) solution, and acidified , and then added with stirring for a certain amount of electrolyte , the silicic acid gel ; acid or sodium silicate solution is added in the thick or silicic acid salts can also generate gel. The silica gel was allowed to stand for several hours so that the aging of soluble salts and washed with hot water at 60 ~ 70 ℃ the dried and activated at about 300 ℃, silica gel can be obtained . The silica gel with cobalt chloride solution and then drying and soaking activation , available color gel . When it is used as a desiccant, is blue before absorption , the absorption becomes red, the color change can be seen from the water absorption degree , and the need for regeneration processing . Silicone is also widely used in the vapor recovery areas , and preparing the oil refining catalyst, etc.
Inorganic silica used as a drying agent , the following aspects may be embodied
1 is mainly used for equipment, instruments, equipment, and other moisture absorption in confined conditions rust .
2 in conjunction with ordinary silica gel desiccant , indicating desiccant to absorb moisture and relative humidity to determine the extent of the environment . As packing silica gel desiccant, widely used in precision instruments , leather, clothing, food , medicines and household appliances.
3 use food-grade silicone because it can be used for baby pacifiers and other supplies in direct contact with the human body , in addition , can also be used to produce silicone skin .
Silicone regeneration should pay attention to the issue
1 , drying regeneration should be careful to gradually raise the temperature , so as not to cause severe drying particles burst, lower recoveries .
2, when the silicone baking regeneration , the temperature is too high will cause changes in the pore structure of silica gel adsorption effect of significantly reducing the impact value. For blue or discoloration silica gel indicator , desorption regeneration temperature should not exceed 120 ℃, otherwise they will be gradually oxidized color developing agent and lose color effect.
3, after the regenerated silica should generally screened to remove fine particles, so the particles evenly.
3 related jargon
Specific surface area : means per g of silica gel has a surface area , including internal and external surface area of ​​the micropores and . – Unit : m / g
Pore ​​volume : Each gram of silica gel inside the pores of the total volume . – Unit: ml / g (ml / g)
Aperture: refers to the internal diameter of the silica pores . – Unit: Angstroms (A 0) or nanometers (nm) 1nm = 10A 0
Adsorption amount : silica gel adsorption at a relative humidity of saturated water vapor , when said amount of the adsorbed amount of adsorption of water vapor . – Unit :%
Bulk density: the quality and volume of the silicone they heap space ratio . – Unit : g / liter (g / l)
PH: PH value is the silica gel after a certain processing conditions , PH value of the aqueous solution containing a proportion of silica gel .
Specific resistance : silica is an indicator of purity . Than the resistance itself is defined as the solution resistance at 1cm distance. Is the specific resistance of the silica gel after a certain processing conditions , the silica gel eluted soluble electrolyte , the electric conductivity than the resistance was measured . Resistance higher than reflected lower water-soluble silica contained in the electrolyte . – Unit : ohm cm (Ω.cm)
Attrition rate : is an indicator of the strength wear-resistant silicone . Refers to silica gel under conditions of loss of abrasion . – Unit :%
Water does not burst rate : is an indicator of the degree of water-resistant silicone water . – Unit :%
4 inorganic silica classification
Silicone based on its pore size is divided into: large pore silica , silica coarse holes , B -type silica gel , silica pores . Due to the different pore structure , adsorption properties so they have their own characteristics . Coarse pore silica gel in the case of high relative humidity has a higher adsorption capacity , pore silica gel in the case of low relative humidity higher than the coarse pore silica gel adsorption , while the B -type silica gel due to the pore structure between the coarse and fine between holes , its adsorption capacity between thick, between pore .
Depending on the use of inorganic silica , silica gel can also be classified into beer , silicone PSA , medical silica gel, indicating silica gel , silica gel desiccant, silica opening agent , such as silica gel toothpaste .
Pores of silica gel
Pore ​​silica gel is colorless or slightly yellow transparent vitreous, its basic quality parameters are as follows : average pitch 2.0-3.0nm, surface area 650-800

M / g, pore volume 0.35-0.4ml / g, the specific heat 0.92KJ/kg. ℃, thermal conductivity 0.63KJ / m. Hr. ℃.
Usage: Apply to dry , moisture, rust . Prevents equipment, instruments, weapons, ammunition, electrical equipment, pharmaceuticals , food , textiles and various other packaging items damp, can also be used as catalyst carrier and dehydration of organic compounds refined . Because of its high bulk density and low humidity absorption effect is obvious characteristics that can be used as an air purifying agent to control air humidity. In the ocean the way there are a wide range of applications , because the goods during transport often deteriorate due to high humidity and moisture , the product can be effective desiccant moisture, so that the quality of the goods is guaranteed . Pore ​​silica is also commonly used in two parallel plates between the sealing window dehumidifier can maintain transparency of the layers of glass .
B -type silica gel
Characters : B -type silica as a milky transparent or translucent pellets or lumps . B -type glue between the pore structure of coarse -pored silica gel , silica pores .

The basic quality parameters : pore volume of 0.60-0.85ml / g, average pore diameter of 4.5-7.0nm, specific surface area of ​​450-650m2 / g.
Uses: mainly used for air humidity regulators, raw materials and catalyst carriers, pet litter, and as chromatography on silica gel and other chemical products.
Coarse pore silica gel
Coarse pore silica called C -type silicone is a silicone , is a highly active adsorption material , is

Amorphous material , its chemical formula is mSiO2 · nH2O. Insoluble in water and any solvent , non-toxic , odorless , chemically stable, does not react with any substance except alkali, hydrofluoric acid . Chemical composition and physical structure of the coarse pore silica , and determines that it has many other features too difficult to replace similar materials : high adsorption properties, good thermal stability, chemical stability, high mechanical strength.
Coarse pore silica white in appearance , there are massive, spherical and spherical micro three products . Coarse -porous spherical silica and the like is mainly used to remove acid gas purification , drying agents , and the insulating oil ; coarse pore silica gel is mainly used for the catalyst carrier block , drying , gas and liquid purification agents .
5 silicone
Silicone Performance
The basic structural unit of the silicone product is made ​​of a silicon – oxide chain section composed of a silicon atom through a side chain with various other organic groups . Thus, in the structure of organic silicon products containing both ” organic group” , but also contain ” inorganic structure” , this particular composition and molecular structure makes it features organic and inorganic feature set in one. Compared with other polymers, silicone products

The most outstanding performance are:
1 . Temperature characteristics
Silicones are silicon – oxygen (Si-O) bond of the main chain structure , C-C bond energy of 82.6 kcal / mol , the bond energy Si-O bond in the organic silicon is 121 kcal / mole , so the high thermal stability of silicone products , high temperature ( or radiation ) molecular bond is not broken , do not break down . Silicone is not only to high temperature , low temperature resistance, but also can be used in a very wide temperature range . Whether it is physical or chemical properties and mechanical properties, temperature dependence is very small.
2 . Weatherability
Silicones of the main chain is -Si-O-, unparalleled key exists , it is not easy to be decomposed by ultraviolet light and ozone. Better than other silicone polymer material thermal stability and resistance to radiation and weathering capabilities . Silicone natural environment life of up to several decades.
3 . Electrical insulating properties
Silicones have excellent electrical insulating properties , dielectric loss , resistance, voltage, resistance, arc resistance, corona , volume resistivity and surface resistivity of the top in the insulating material etc. , and their performance is affected by temperature and frequency electrical little effect . Therefore, they are a stable electrically insulating material , are widely used in electronics and electrical industry. Silicones have excellent heat resistance in addition , it also has excellent water repellency , the electrical equipment which is used under wet conditions having a high reliability protection .
4 . Physiologically inert
Silicone compounds are known in the least one active compound . They are extremely resistant to biological aging , and animal body without rejection , and has better anti- clotting properties.
5. Low surface tension and low surface energy
Main chain of the silicone is very soft, the force between molecules is much weaker than the hydrocarbon , therefore , lower viscosity than the same molecular weight hydrocarbons , weak surface tension , surface energy is small, the film forming ability . This low surface tension and low surface energy which is the main reason for many applications to obtain : the excellent performance of the hydrophobic , anti-foaming , foam stability, release , lubrication, coating and the like.
Use of silicone
Since these silicones excellent properties , it is very wide range of applications . It

Not only as aviation, cutting-edge technology, special materials used in military technology sector , but also for the various sectors of the national economy , its scope of application has been extended to : construction, electrical and electronics, textiles, automobiles, machinery , leather, paper, chemicals , light industry, metal and paints, pharmaceuticals and medical .
Category 6 silicone
Silicone divided into silicone rubber, silicone resin, silicone three categories.
Depending molding silicone products can be divided into three categories Department
Molded silicone products
Molded silicone products are usually placed in the mold by adding high-temperature vulcanizing agent solid vulcanized silicone raw materials by applying pressure machines, high temperature sulfur of forming a solid , molded silicone hardness is usually 30 ° C-70 ° C. Raw materials in accordance with creams recall Pantone color card color, shape of the mold determines the shape of the molded silicone products , molded silicone products silicone industry is currently the most widely used one . Mainly used only silicone industrial parts, buttons, silicone gifts , silicone wristbands , silicone watches, key cases, mobile phone sets , silicone kitchenware, silicone pad, Ice Cube , cake and so on.
Extruded silicone products
Extruded silicone products usually through extrusion machine extrusion molding silicone , silicone extrusion shapes are generally long , tubular free to cut, but there are limitations shape silicone extrusion , medical equipment, food machinery in a wide range of to use.
Liquid silicone products
Liquid silicone injection molding silicone products through injection molding , product flexibility , hardness can reach 10 ° C-40 ° C, because of its soft features , in emulation of human organs , medical Guijiaoxiongdian , and other widely used.
Specialty Silicone Products
Specialty silicone products is based on the chemical properties of silicone or some add auxiliary materials , specialty silicone products also have a high temperature ( up to 330 degrees ) , food grade ( full compliance with U.S. FDA, LFGB standard ) , medical grade, flame retardant by adding auxiliary materials can also have , luminous , negative ions, color, and other characteristics.
7 Silicone Rubber classified edit
Silicone RTV silicone is mainly divided into high-temperature vulcanized silicone
RTV silicone Introduction and classification
RTV silicone (RTV) is a sixties advent of a new type of silicone elastomer , the most significant feature of this rubber is at room temperature without heating , such as pressure can be cured in situ , extremely easy to use . Thus , came on fast become an important part of the silicone products . Today, RTV silicone has been widely used as adhesives , sealants, protective coatings, potting and molding materials , in all walks of life has its purpose.
RTV silicone its packaging can be divided into single -component and two -component RTV silicone, by curing mechanism can be divided into condensation and molding. Therefore , by component RTV silicone , curing mechanism and the use of technology can be divided into three types, namely single-component RTV silicone, two-component RTV silicone condensation-type and two-component RTV silicone molding added . These three series RTV silicone has its own characteristics : the advantages of one-component RTV silicone is easy to use, but deep curing speed more difficult ; advantages of two-component RTV silicone that hold heat curing , shrinkage is small, no swelling, no stress, curing can be performed on both the inside and the surface, deep cure ; plus RTV curing time mainly depends on the temperature of the silica gel , and therefore , can be controlled by temperature adjustment cure rate .
Among the many synthetic rubber , silicone is a leader in it. It has a non-toxic , tasteless , not afraid to withstand cold temperatures and characteristics , in the ninety degrees below zero Celsius Baidu and ” poised “, ” without blinking an eye ,” still lose the original strength and elasticity. There are good electrical insulation silicone , resistance to oxygen aging resistance , light resistance to aging and mildew resistance , chemical stability. Because of these excellent properties , making silicone get a very broad and important uses in modern medicine . In recent years, the hospitals, research institutes and factories work together successfully trial a variety of silicone medical supplies .
Silicone Earplugs : wear comfortable, noise can be a good barrier to protect the eardrum.
Silicone vacuum extraction device : easy to operate , safe to use , according to the size of the fetal head deformation , fetal scalp will not be sucked up attracting avoid damage to the scalp and intracranial hematoma and other ills , can greatly reduce the pain of childbirth in pregnant women during childbirth .
Silicone artificial blood vessel : a particular physiological function, and the body can be ” intimacy ” , it does not exclude the human body , after a certain time, it will complete with the body tissue is extremely good stability up case .
Silicone tympanic membrane repair piece : its thin, flexible film , finish and good toughness . Is an ideal material for repair of the eardrum , and easy to operate , the effect is quite good.
There are also artificial trachea silica , artificial lung, artificial bone , duodenum silicone tube, the effect is very good.