助浸剂对草酸浸出氰化尾渣中赤铁矿效果的影响  

Effect of Additives on Leaching of Hematite from Cyanide Tailings with Oxalic Acid

作　　者：党晓娥[1,2] 冯磊 张婷 李林波 DANG Xiaoe;FENG Lei;ZHANG Ting;LI Linbo(College of Metallurgical Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China;Key Laboratory for Gold and Resources of Shaanxi,Xi′an 710055,China)

机构地区：[1]西安建筑科技大学冶金工程学院,西安710055 [2]陕西省黄金与资源重点实验室,西安710055

出　　处：《有色金属（冶炼部分）》2024年第1期21-32,共12页Nonferrous Metals（Extractive Metallurgy)

基　　金：国家自然科学基金资助项目(51974221)。

摘　　要：为揭示浸出液中Fe^(3+)的形态分布对焙烧氰化尾渣中赤铁矿浸出效果的影响,研究了H_(2)C_(2)O_(4)、H_(2)C_(2)O_(4)-H_(2)SO_(4)和H_(2)C_(2)O_(4)-K_(2)C_(2)O_(4)对赤铁矿浸出效果的影响,并采用响应面法对H_(2)C_(2)O_(4)-K_(2)C_(2)O_(4)浸出赤铁矿工艺进行了优化。结果表明:Fe^(3+)的形态分布直接影响赤铁矿的浸出效果。H_(2)C_(2)O_(4)与K_(2)C_(2)O_(4)作为除铁剂,n(H_(2)C_(2)O_(4))/n(K_(2)C_(2)O_(4))摩尔比、(C_(2)O_(4)^(2-))_(T)过量倍数及浸出温度影响浸出pH,而pH和c(C_(2)O_(4)^(2-))_(T)应满足浸出的Fe^(3+)转化成Fe(C_(2)O_(4))_(3)^(3-),Fe^(3+)只有以Fe(C_(2)O_(4))_(3)^(3-)形态存在,才能缩短赤铁矿浸出时间、提高赤铁矿浸出效果。H_(2)C_(2)O_(4)-K_(2)C_(2)O_(4)除铁优化条件为:n(H_(2)C_(2)O_(4))/n(K_(2)C_(2)O_(4))=1.03、(C_(2)O_(4)^(2-))_(T)为理论量的1.37倍、浸出温度94℃、液固比L/S=5mL/g、时间30min。在优化条件下,实际值和预测值分别为98.42%和97.73%,相对误差为0.69个百分点。各因素对除铁效果影响大小排序为(C_(2)O_(4)^(2-))_(T)过量倍数、浸出温度、n(H_(2)C_(2)O_(4))/n(K_(2)C_(2)O_(4)),其中n(H_(2)C_(2)O_(4))/n(K_(2)C_(2)O_(4))与浸出温度有一定的交互作用。H_(2)C_(2)O_(4)-K_(2)C_(2)O_(4)浸出焙烧氰化尾渣中赤铁矿结果进一步证明,草酸-草酸盐混合浸出体系是一种高效除铁剂,且浸出液中的铁资源化利用工艺简单,其优势是现有除铁剂无法比拟的。In order to reveal the influence of species distribution of Fe^(3+)in the leachate on the leaching effect of hematite in roasting cyanide tailings,the leaching effects of H_(2)C_(2)O_(4),H_(2)C_(2)O_(4)-H_(2)SO_(4) and H_(2)C_(2)O_(4)-K_(2)C_(2)O_(4) on hematite were studied.Response Surface Method (RSM)was used to optimize the leaching process of hematite with H_(2)C_(2)O_(4) and K_(2)C_(2)O_(4).The results show that the species distribution of Fe^(3+)affects the leaching effect of hematite,when H_(2)C_(2)O_(4) and K_(2)C_(2)O_(4) were used as iron removal agents,n(H_(2)C_(2)O_(4))/n(K_(2)C_(2)O_(4))mole rate,the excess multiple of(C_(2)O_(4)^(2-))_(T),and temperature affect leaching pH value and c (C_(2)O_(4)^(2-))_(T),and they should be sufficient for Fe^(3+)conversion to form Fe(C_(2)O_(4))_(3)^(3-).Fe^(3+)exists only in form of Fe(C_(2)O_(4))_(3)^(3-),the leaching time of hematite can be shortened and the leaching rate of iron can be improved.The iron removal optimization conditions with H_(2)C_(2)O_(4)and K_(2)C_(2)O_(4) are as follows:n(H_(2)C_(2)O_(4))/n(K_(2)C_(2)O_(4))=1.03,(C_(2)O_(4)^(2-))_(T) dosage of 1.37times of the theoretical amount,94℃,L/S=5 mL/g,and 30 min.Under the optimal conditions,the actual and predicted values are 98.42%and 97.73%respectively,and the relative error is 0.69percentage point.The effect of the factors on iron removal is sorted as (C_(2)O_(4)^(2-))_(Texcess) ratio,leaching temperature,and n(H_(2)C_(2)O_(4))/n(K_(2)C_(2)O_(4)).Among them,the interaction between n(K_(2)C_(2)O_(4))/n(K_(2)C_(2)O_(4))and leaching temperature has some interaction.The results of K_(2)C_(2)O_(4)-K_(2)C_(2)O_(4) leaching hematite from the roasting cyanide tailings further prove that the oxalic acid-oxalate leaching system is an efficient iron removal agent.Moreover,the process of iron resource utilization in the leaching solution is simple,and its advantages are incomparable to the existing iron removal agents.

关 键 词：焙烧氰化尾渣 浸出 赤铁矿 响应面法(RSM) 优化 

分 类 号：X758[环境科学与工程—环境工程]