(中南大學(xué) 資源加工與生物工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 基于氧化鐵與硫酸反應(yīng)的熱力學(xué)原理，采用硫酸熟化-水浸法對(duì)高硫高砷金精礦氧化焙砂進(jìn)行預(yù)處理，以脫除鐵氧化物，破壞其對(duì)金的包裹，提高金浸出率。結(jié)果表明，在適宜的硫酸含量下，赤鐵礦與硫酸反應(yīng)的產(chǎn)物硫酸鐵可轉(zhuǎn)化為板鐵礬HFe(SO4)2·4H2O 晶體，降低了產(chǎn)物濃度，從而使赤鐵礦繼續(xù)溶解，提高了鐵脫除率；適當(dāng)升高溫度可促進(jìn)擴(kuò)散的進(jìn)行，從而使鐵的脫除更加徹底。焙砂的氰化浸金率在脫除鐵氧化物后顯著提高。對(duì)于某鐵含量為31.25%(質(zhì)量分?jǐn)?shù))金含量為84.27 g/t 的焙砂，當(dāng)熟化條件為硫酸含量75%、硫酸過(guò)剩系數(shù)1.4、熟化溫度250 ℃、熟化時(shí)間1 h 時(shí)，焙砂中殘余鐵含量降至7.23%，此時(shí)金浸出率可達(dá)97.51%。
關(guān)鍵字: 高硫砷金礦；焙砂；硫酸熟化；浸金；除鐵
（School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China）
Abstract:Based on thermodynamics between iron oxides and sulfuric acid,a pretreatment process of sulfuric acid-curing and leaching was used to remove iron,release packaged gold and enhance gold leaching rate. The results show that the product of hematite and sulfuric acid,ferric sulfate,converts to rhomboclase HFe(SO4)2·4H2O under a suitable H2SO4 acidity,which can lessen the product concentration,continue the hematite dissolution and improve the iron removal rate. A reasonably higher temperature during curing process leads to a higher iron removal rate. The pretreatment works effectively. For calcine containing Fe of 31.25%(mass fraction) and Au of 84.27 g/t,the gold leaching rate reaches 97.51% and the residual iron in calcine is reduced to 7.23% after a pretreatment of sulfuric acid content 75%,excess coefficient of sulfuric acid 1.4,curing temperature 250 ℃ and curing time 1 h.
Key words: gold ores with high sulfur and arsenic; calcine; sulfuric acid-curing; gold leaching; iron removal
