Dissolution behavior of cobalt from WC-Co hard metal scraps by oxidation and wet milling process
Dissolution behavior of cobalt from WC-Co hard metal scraps by oxidation and wet milling process
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DOI：
10.1016/j.hydromet.2014.01.004
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发表时间：
2014-03-01
期刊：
影响因子：
4.7
通讯作者：
Son, Seong-Ho
中科院分区：
文献类型：
--
作者：
Kim, Sunjung;Seo, Bosung;Son, Seong-Ho
本文主要研究了湿法球磨从WC-Co硬质合金废料中溶解Co的工艺。考虑到世界范围内钴的沉积稀少且不均匀，开发一种相对快速且低酸浓度的从WC-Co硬质合金废料中回收钴的方法具有重要意义。WC-Co废料被充分氧化，产生WO 3和CoWO 4的混合物。在pH小于2的硫酸溶液中，CoWO 4容易分解生成可溶性的CoSO 4和不溶性的钨酸，通过改变溶液的浓度、温度和搅拌速度等溶解条件，测定Co溶解效率随溶解时间的变化。添加2体积%向溶液中加入过氧化氢大大提高了Co的溶解速率。通过在具有过氧化氢的IM硫酸溶液中经由湿磨破坏钨酸层的Co溶解比Co在IM硫酸溶液中的简单化学溶解快四倍。湿磨是一种从WC-Co废料中回收Co的省时工艺，其使用相对低浓度的酸溶液。(C)2014爱思唯尔有限公司版权所有。
Wet milling was fundamentally investigated as a process for dissolution of Co from WC-Co hard metal scrap in this study. The development of a relatively fast and low acid-concentration recycling method of Co from WC-Co hard metal scrap is significant, considering the rare and uneven deposition of Co worldwide. WC-Co scraps were fully oxidized, resulting in a mixture of WO3 and CoWO4. CoWO4 was readily decomposed to produce soluble CoSO4 and insoluble tungstic acid in sulfuric acid solution of pH 2 or less. Dissolution conditions such as the concentration, temperature, and stirring rate of the solution were varied to determine changes in Co dissolution efficiency with dissolution time. Adding 2 vol.% hydrogen peroxide to the solution augmented the Co dissolution rate considerably. Co dissolution by disruption of the tungstic acid layer via wet milling in 1 M sulfuric acid solution with hydrogen peroxide was four times faster than simple chemical dissolution of Co in 1 M sulfuric acid solution. Wet milling is a time-efficient process to recycle Co from WC-Co scraps which uses a relatively low concentration acid solution. (C) 2014 Elsevier B.V. All rights reserved.