Amalgams processing

Alzodep Al3Zr [12004-Amalgam Amalgam process Amalgams... 

Silver is usually extracted from high-grade ores by three common processes that have been known for many years. These are amalgamation, leaching, and cyanidation. In one amalgamation process, ore is crushed and mixed with sodium chloride, copper sulfate, sulfuric acid, and mercury, and roasted in cast iron pots. The amalgam is separated and washed. Silver is separated from its amalgam by distillation of mercury. 

Nuclear Fuel Services, Inc. (NFS), developed the commercially available DeHg process for the low-temperature treatment of mercury-contaminated hazardous and mixed wastes. The technology uses a proprietary amalgamation process to convert mercury into a nonhazardous solid. The technology is now offered by Advanced Recovery Systems, Inc. The developer claims the technology can be used on sludges, hazardous and mixed wastes, and mercury-contaminated wastes containing tritium. 

When he demonstrated de Medinas cold amalgamation process to the Viceroy, the latter offered him suitable reward, ordered him to make the secret known at Potosi (Bolivia), and added that the most important wedding in the world was about to take place the marriage of Mount Potosi (silver) to Mount Huancavelica (mercury) (60). 

Pedro Fernandes de Velasco demonstrates his cold amalgamation process for the recovery of silver from the ores of Mount Potosi (Bolivia). 

These results show how imperfect is this method and hence, in the great metallurgical centres, 11,6 method now preferred is to separate the silver from the copper, either by the amalgamation of tho matts or by that of tho black-copper. - These operations are effected in a manner analogous to the Saxon amalgamation process, which has been already described, so that it will be only necessary to indicate briefly the special circumstances resulting from the nature of the materials submitted to the operation. 

Fiti. 5. Typical RuCT-coated Ti-wire anode for chlorine evolution in the amalgam process (courtesy of Heraeus Elektroden GmbH). 

The current-time curve corresponding to the application of the second potential is very sensitive to the presence of assimilation or amalgamation processes at spherical electrodes. In order to check this in Fig. 4.2, it can be seen the... 

Various modifications of the amalgamation process have been employed in Mexico and Chile, but in recent years this method has been to a great extent supplanted by the cyanide process, described on p. 291. Extraction by amalgamation is more difficult with silver than with gold. Mercury liberates silver rapidly from the chloride, bromide, and iodide, and very slowly from the sulphide. Other ores have to be converted... 

The pan-amalgamation process has found more favour than the patio process. The ore in the form of fine sludge is stirred in iron pans with a mixture of mercury, common salt, and cupric sulphate. When the action is complete, the excess of mercury is drained off, and the amalgam is allowed to settle, and then decomposed by heat. In the Boss system the process is continuous, a series of pans and settlers being employed. Some silver ores, notably those containing sulphides of arsenic, antimony, copper, iron, and zinc, are roasted with common salt before amalgamation. 

The amalgamation process is used for native silver. The ore is treated with mercury, which dissolves the silver. The liquid amalgam is then separated from the gangue and distilled, the mercury collecting in the receiver and the silver remaining in the retort. 

Ores of silver native silver, argentite, cerargyrite (horn silver). Metallurgy of silver cyanide process, amalgamation process, Parkes process. O mpoimds of silver silver oxide, silver chloride, silver bromide, silver iodide, silver ammonia complex, silver cyanide complex, silver thiosulfate complex, silver nitrate. 

This hydrogen is, however, mostly used in house. Hydrogen is also produced in other petrochemical and chemical processes (synthesis of olefins, ethyne, styrene, acetone). Coke oven gas contains over 50 volume % of hydrogen, from which it can be isolated. Finally hydrogen occurs as a valuable byproduct in chloralkali-electrolysis (directly with the diaphragm process or indirectly with the amalgam process and hydrochloric acid hydrolysis) see Section 1.7.3.3. The electrolysis processes account for less than 5% of the worldwide production of hydrogen. 

Amalgam process Cooled aqueous solutions of sodium hydrogen sulfite are reduced with sodium amalgam (from sodium chloride electrolysis). The sodium dithionite formed is recovered by crystallization. 

So, the addition of Eqs. (1), (2), and (4) gives the overall reaction of the so-called amalgam process for the production of chlorine and alkali from sodium chloride... 

Comparing the amalgam process and the diaphragm process beforehand, the diaphragm variety has the advantage of a lower electrolysis voltage. But the alkali product is a mixture of alkali NaOH and... 

Caustic Alkali Sodium hydroxide solution from the decomposer of the amalgam process usually has a concentration of 50% and a chloride content of only 5-50 mg kg-1. It is cooled down from 80-120 °C to 40-60 °C in steel pipes, Ni-, or Incolloy coolers. Any particles of graphite from the decomposer material or traces of mercury are removed by centrifuges, candle filters, or precoated leaf filters. 

---