镍冶炼渣矿物学特征对浮选回收镍、铜的影响

Influence of mineralogical characteristics of nickel smelting slag on recovery of nickel and copper by flotation

为回收利用镍冶炼渣中的镍和铜等有价金属,本文以我国某镍冶炼渣为研究对象,利用多种矿物学特征分析手段,深度解析镍冶炼渣的矿物学特征对浮选回收渣中镍、铜回收的限制,并提出利用源头焙烧改性优化有价金属镍、铜的结晶状态,进而提高镍、铜浮选回收率。研究结果表明,镍冶炼渣中主要的有价金属镍、铜的品位分别为0.88%和0.31%,在可浮性较差的氧化态和残余态中的占比达20%左右,可浮性较好的镍、铜主要赋存于镍黄铁矿、斑铜矿和硫镍矿中,但是这三种矿物相多以微细粒不规则状散乱分布在硅酸盐矿物相间,难以实现单体解离;镍、铜较差的结晶状态导致其浮选回收率分别仅有24.61%和38.77%,优化镍铜在渣中的结晶状态成为提高其浮选回收率的关键所在。在焙烧改性后,镍、铜在可浮性较好的金属态和硫化态中的占比均高达90%以上,其浮选回收率也分别提高了41.55%和41.23%。

In order to recycle valuable metals such as nickel and copper in nickel smelting slag,a nickel smelting slag in China is taken as the research object,the limitations of mineralogical characteristics of nickel smelting slag on the recovery of nickel and copper in flotation are deeply analyzed,and it is proposed to optimize the crystallization state of valuable metals nickel and copper by source roasting modification,so as to improve the recovery rate of nickel and copper flotation.The results show that,the grades of nickel and copper are 0.88% and 0.31%,respectively,accounting for about 20% of the oxidation state and residual state with poor floatability,and the nickel and copper with good floatability are mainly found in nickel pyrite,bornite and polydymite,but these three mineral phases are mostly scattered among the silicate minerals in the form of fine grains and irregularities,and it is difficult to achieve monomer dissociation,and the poor crystalline state of nickel and copper leads to the flotation recovery rate of only 24.61% and 38.77%,respectively.Optimizing the crystallization state of nickel-copper in the slag has become the key to improving the flotation recovery.After roasting modification,the proportion of nickel and copper in the metal state and sulfide state with good floatability is over 90%,and the flotation recovery rate is also increased by 41.55% and 41.23%respectively.