Tin(II) Chloride Dihydrate CAS 10025-69-1

In terms of elemental analysis, stannous chloride is mainly used as an analytical reagent for the determination of silver, arsenic, molybdenum, mercury, etc. The content of molybdenum in ore was determined by stannous chloride reduction potassium thiocyanate spectrophotometry. The experiment uses tin protochloride, potassium thiocyanate and phosphate to treat the standard sample and the ore sample solution, wherein stannous chloride is the reducing agent, potassium thiocyanate is the color complexing agent, and phosphate is the stabilizing agent. Under the conditions, the standard curve equation A=0.9997c~0.0008 was obtained, and the molybdenum content in the ore sample was analyzed and determined by using this relational formula. The precision of the determination results was high, which met the determination requirements. Using creatinine correction-alkaline stannous chloride reduction-cold atomic absorption spectrometry to determine mercury content in urine, this method is fast, simple and has high recovery rate, and is suitable for the determination of large-scale samples.

In addition, stannous chloride is also widely used in the analysis of iron, phosphorus, germanium, tungsten, platinum and other elements. For the determination of iron in iron ore, the SnCl2-A-B three-system method is generally used, and the mercury-free and chromium-free titration method of stannous chloride-titanium trichloride-potassium permanganate is used to determine iron. Determination of iron in ore, the result is satisfactory. Using stannous chloride-methylene blue-potassium dichromate mercury-free titration method and using methylene blue as pre-reduction indicator, a mercury-free titration method for total iron in iron ore by stannous chloride reduction and potassium dichromate was established. analysis method.

The results show that: when SnCl2 is used as the pre-reducing agent and methylene blue is used as the pre-reduction indicator, 2~3 drops of methylene blue with a concentration of 2.94g/L are added dropwise, and the color changes at the pre-reduction end point and titration end point are sharp. Two kinds of iron ores were analyzed, and the standard method was used to conduct a control test. It was found that at the 95% confidence level, there was no significant difference in the precision of the measured values ​​obtained by the two methods, and there was no significant difference between the average values of the two groups of data. Significant difference. When using stannous chloride reduction spectrophotometry to measure total phosphorus, glycerol is used instead of water as the medium of stannous chloride solution, which solves the problem of limited use time of stannous chloride solution, has the advantages of saving reagents and time, and Long-term experiments have proved that the correlation between the stability of the chromogenic solution and the calibration curve is better when glycerol is used as the medium, and it can be popularized and used in practical work.

In the field of organic synthesis, stannous chloride is mostly used as a catalyst for esterification reactions. In traditional industry, the synthesis of ester usually uses concentrated sulfuric acid as catalyst. Although concentrated sulfuric acid has the advantages of strong acidity, good catalytic activity, and mature process, it has serious corrosion on equipment, troublesome post-treatment, and easily produces waste acid sewage. When stannous chloride is used to catalyze the esterification reaction, not only the catalytic reaction time is short, the yield of ester is high, but also the reaction conditions are mild and the aftertreatment is simple.

In addition, it has been reported in the literature that stannous chloride can effectively catalyze the three-component “one-pot” synthesis of carbamate-based alkylnaphthol from 2-naphthol, aromatic aldehyde and carbamate under the condition of no solvent and 60 °C derivative. Compared with the reported catalysts, stannous chloride has better catalytic activity. The method has the advantages of high yield, short reaction time, raw material saving, simple and clean reaction process, and environmental friendliness. It can be seen that the role of stannous chloride in organic synthesis is becoming more and more important. In recent years, as a new type of Lewis acid ionic liquid, the SnCl-ionic liquid composite catalytic system has been gradually paid attention to because of its good catalytic activity and stability, can effectively reduce the temperature of the reaction system, shorten the reaction time and be friendly to the environment. .

Using the ionic liquid 1-butyl-3-methylimidazolium chloride (［Bmin］Cl) and the double salt of stannous chloride (SnCl2) as the catalyst and L-lactic acid as the raw material, PLA was synthesized by melt polycondensation. The results show that the [Bmin]Cl/SnCl2 catalytic system can significantly reduce the reaction temperature, shorten the reaction time, and increase the Mη of PLA. Using stannous chloride and caprolactam as raw materials, SnCl2-caprolactam ionic liquid was used to catalyze the synthesis of ethyl acetate. It was found that the catalyst had good stability and high reaction esterification rate.

In addition, the reusability of stannous chloride-ionic liquid catalyst is also one of the reasons for its rapid development. Using terephthalic acid and 2-ethylhexanol as raw materials, diisooctyl terephthalate (DOTP) was synthesized by esterification with butylpyridine chloride-stannous chloride ionic liquid as a catalyst. It was found that this method not only has the characteristics of fast reaction speed, high conversion rate, no pollution, and environmental protection, but also the yield of DOTP can still reach more than 90% when the catalyst is reused 5 times.

In terms of separation, stannous chloride is mostly used in the flotation separation of platinum, palladium, rhodium, osmium and other precious metals in the form of multiple associations. Compared with the traditional solvent flotation separation and foam flotation separation, the stannous chloride multiple association system has the advantages of not using toxic organic solvents, easy operation, no special equipment, high separation efficiency, fast phase separation, It has the advantages of less reagent consumption and low analysis cost. Study the method of flotation and separation of platinum in stannous chloride-malachite green-water system in the presence of ammonium sulfate in hydrochloric acid medium. Under the optimal experimental conditions, the flotation rate of platinum can reach 100.0%, and it can be completely separated from common base metals .

The flotation behavior experiment of the stannous chloride-hexadecyltrimethylammonium chloride system on the Os(Ⅳ)-trichlorostannate complex anion in the presence of sodium chloride shows that in the hydrochloric acid medium, the system can be separated by flotation Os( Ⅳ ), its flotation rate is 95.2%~98.0%. Compared with the traditional separation method of osmium, distillation separation, this method is easy to operate, requires less equipment, avoids the harm of OsO4 vapor to the operator, and is suitable for the separation of a large number of matrix metal elements before the determination of Os.