کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6672367 | 1427590 | 2018 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Thiosulphate leaching of silver from an arsenical refractory ore
ترجمه فارسی عنوان
شستشو تیوسولفات نقره از سنگ آهک مقاوم به آرسنیک
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کلمات کلیدی
سنگ معدن، نقره، سنگ زنی فوق العاده تیستولفات، بازیافت نقره،
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
چکیده انگلیسی
Thiosulphate leaching has received particular attention in recent years as an environmentally benign alternative to cyanide leaching. In this study, thiosulphate leaching combined with ultra-fine grinding (UFG) was studied for silver extraction from an arsenical refractory ore. Direct cyanidation of the ore (d80: 50â¯Âµm) led to a low silver extraction ofâ¯â¤â¯70% over 24â¯h. leaching period. Extraction of silver in cyanide leaching was improved to 85% after ultra-fine grinding. In comparison, up to 98% of silver extraction was achieved in thiosulphate leaching system after ultra-fine grinding of the ore down to 5â¯Î¼m (d80) in a stirred mill. Furthermore, thiosulphate leaching is more selective than cyanide leaching with only negligible leaching of arsenic, antimony and other metals observed in this study. This is of particular importance considering the environmental concern for the presence of arsenic in cyanide leaching solutions and effluents. Effects of thiosulphate (0.2-0.6â¯M Na2S2O3), ammonia (0.04-0.52â¯M NH3) and copper (0.02-0.11â¯M CuSO4) on the extraction of silver were investigated using a Box-Behnken design. Statistical analysis of the experimental data (%Ag extraction at 8â¯h.) confirmed that all the parameters have quadratic effects in that the extraction of silver tends to improve with increasing their concentration up to a critical level above which a reverse trend occurs. The addition of a small amount (0.1â¯M EDTA, 50â¯mg/L CMC) of ethylenediaminetetraacetic acid (EDTA) and carboxymethyl cellulose (CMC) improved (by â¼20-30%) silver extraction and reduced thiosulphate consumption by â¼20%. Using nickel sulphate in place of CuSO4 also improved silver extraction with concurrent decrease in thiosulphate consumption. Recovery of silver from real pregnant leach solutions using sodium borohydride (NaBH4) as the precipitating agent was also investigated in detail. A high silver recovery of â¥98% was achieved under suitable conditions. These findings highlight that ammoniacal thiosulphate leaching in combination with ultra-fine grinding can be used as a suitable and environmentally sound alternative to cyanide leaching and the additives such as EDTA and CMC, and nickel in place of copper can improve the extraction of silver from refractory silver ores.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Minerals Engineering - Volume 122, 15 June 2018, Pages 285-295
Journal: Minerals Engineering - Volume 122, 15 June 2018, Pages 285-295
نویسندگان
Oktay Celep, Pelin Altinkaya, Ersin Y. Yazici, Haci Deveci,