In order to remove arsenic from the alkaline solution for reuse, the leaching slurry should be concentrated and filtered. The unit area of ​​concentration is 0.58~ 0.85 meters 2 (tons, stay up all night), when adding polyacrylamide, can be reduced to 0.18~ 0.23 meters 2 (tons, stay up all night). Concentration results of the leached pulp product indicate that the amounts of -6 and -15 microns are actually equal. The unit productivity of the filter is 3~7 tons / (m 2 , day and night), that is, the usual process equipment can be utilized.
The obtained alkaline solution contains As 2~ 3.9 grams / decimeter 3 , S 2.8~ 8.9 grams / decimeter 3 . The remaining concentration of sodium hydroxide is 30~ 35 grams / decimeter 2 . Most of the arsenic in the alkaline solution can be precipitated by the method of adding lime, and the mother liquor can be recycled (the residual concentration of As does not exceed 0.3~) 0.4 g / decimeter 3 ). Part of the sulfur precipitates together with arsenic. The precipitate contains 37.6% calcium arsenate and 16.8% calcium sulfate , which means that the product is actually in line with the process requirements of arsenate. Sodium hydroxide is regenerated 20 to 30% during the treatment . To solution purification to the limit allowable concentration, may be added in the phosphate solution for deep purification.
According to the results of the concentrate treatment research, the following processes are recommended, including: air jet grinding (milling the prepared product to a particle size of -15 microns), leaching with sodium hydroxide solution, adsorption cyanidation, and pre-existing products according to production. metallic gold and silver flow to the desorption, the basic repeated purification mother liquor for recycling or disposal (FIG. 2). Technical and economic calculations show that the cost of concentrate processing is 30% lower than the actual situation of MJI3 after arsenic removal .
The process can be tested on a large scale to solve the possibility of practical application.
Volatile Silicone Fluid
Volatile Silicone Fluid,Cyclopentasiloxane (And) Cyclohexasiloxane,Methyl Trimethicone,Caprylyl Trimethicone
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