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研究了从银的卤化物和硫酸盐中回收金属银的火法冶金工艺。该工艺由含银化合物与碱金属碳酸盐或氢氧化物在熔态的反应组成。所发生的反应如下:2AgCl_(熔)+Na_2CO_3_(熔)→2Ag_(熔)+2NaCl_(熔)+CO_2_(气)1/2C_2_(气);Ag_2SO_4_(熔)+NA_2CO_3_(熔)→2Ag_(熔)+Na_2SO_4_(熔)+CO_2_(气)+1/2O_2_(气);和2AgCl_(熔)+2NaOH_(熔)→2Ag_(熔)+2NaCl_(熔)+H_2O_(气)+1/2O_2_(气).该过程在约1000℃下进行熔炼反应产出熔体金属银和熔体碱金属盐或硫酸盐。研究了影响以氯化银回收金属银的三个因素:熔炼温度、熔炼时间和碳酸钠加入量。建议也可以使用其它纯碱金属碳酸盐、氢氧化物或它们的混合物。用这个工艺也可从溴化银和硫酸盐中回收银。此外,表明在低温熔炼接着浸出生产银粉的工艺具有95～98%的金属回收率。氯化银是贵金属工业一种普通的付产物,在照相业和材料加工业的废料中也有。尽管从这些物料中回收金属银发明了一些方法,但总是昂贵和复杂的。所研究过的方法包括置换、电解和化学沉淀。置换工艺是将更活性的金属例如锌加至稀盐酸(5%)或稀硫酸(5%)的氯化银水溶液中。反应迅速且放热,因此必须小心进行以免过沸和氢逸出。所要求设备简单且便宜,过程用手控或自动控制,约99%的银以灰色海棉物被回收,它在熔炼前必须洗
The pyrometallurgical process was studied for the recovery of metallic silver from silver halides and sulfates. The process consists of the reaction of a silver-containing compound with an alkali metal carbonate or hydroxide in the molten state. The reactions that occur are as follows: 2AgCl_ (melting) + Na_2CO_3_ (melting) → 2Ag_ (melting) + 2NaCl_ (melting) + CO_2_gas 1 / 2C_2_ (gas); Ag_2SO_4_ (melting) + NA_2CO_3_ (melting) → 2Ag_ ) + Na_2SO_4_ (melting) + CO_2_ (gas) + 1 / 2O_2_ (gas); and 2AgCl_ (melting) + 2NaOH_ (melting) → 2Ag_ (melting) + 2NaCl_ (melting) + H_2O_ (gas) The process is conducted at a temperature of about 1000C to carry out a smelting reaction to produce molten metallic silver and a molten alkali metal salt or sulfate. Three factors affecting the recovery of metallic silver with silver chloride were studied: smelting temperature, smelting time and the amount of sodium carbonate added. It is also advisable to use other purely alkali metal carbonates, hydroxides or their mixtures. Silver can also be recovered from silver bromide and sulfate using this process. In addition, the process which shows the leaching of the silver powder for production at a low temperature has a metal recovery of 95 to 98%. Silver chloride is an ordinary by-product of the precious metal industry, as well as waste materials in the photographic and materials processing industries. Although some methods have been invented to recover metallic silver from these materials, it is always expensive and complicated. The methods studied include displacement, electrolysis and chemical precipitation. The displacement process is to add a more reactive metal, such as zinc, to an aqueous solution of silver chloride diluted with dilute hydrochloric acid (5%) or dilute sulfuric acid (5%). The reaction is rapid and exothermic, so care must be taken to avoid over boiling and hydrogen escaping. The equipment required is simple and inexpensive, the process is controlled by hand or automatically, about 99% of the silver is recovered as gray sponge, which must be washed before melting