黑龙江某铜钼混合精矿絮凝沉降性能及机理研究

Flocculation and settling performance and mechanism of a coppermolybdenum mixed concentrate in Heilongjiang Province

黑龙江某铜钼混合精矿矿物成分复杂,矿样中-30μm粒级含量占45.56%,微细颗粒含量高,该精矿因成分复杂且微细粒含量高导致精矿浓缩池的絮凝沉降作业面临着沉降慢、溢流浊度高的巨大难题。为探究该精矿的絮凝沉降性能及相关机理,首先,对该样品进行单因素絮凝沉降试验,以沉降高度和上清液浊度为指标考察絮凝剂分子量、絮凝剂浓度、絮凝剂单耗量、矿浆浓度和矿浆pH值对其絮凝沉降效果的影响;其次,利用傅里叶红外光谱对沉降产物进行分析,探究矿物颗粒与絮凝剂之间的配位模式和作用方式;最后,借助分子动力学模拟结果分析样品中各矿物与絮凝剂分子和水分子之间的作用关系。物理结果表明,该样品在阴离子型聚丙烯酰胺(APAM)分子量1000万、配制浓度1.60‰、单耗量25g/t、矿浆浓度25%和矿浆pH=11时絮凝沉降效果最优;红外谱图分析结果表明,APAM与矿物表面发生了氢键吸附和化学吸附;分子动力学结果表明,4种主要矿物与APAM的絮凝吸附均为自发过程,且APAM分子在4种矿物表面均紧密分布,而水分子主要分布在黄铜矿和辉钼矿表面。本文研究结果可为微细粒铜钼混合精矿的絮凝沉降工艺及新型絮凝剂分子的设计开发提供科学依据。

The mineral composition of a copper-molybdenum mixed concentrate is complex in Heilongjiang Province.The content of-30μm particles in the ore sample accounts for 45.56%,and the content of fine particles is high.The complex composition and high content of fine particles make the sedimentation operation of the concentrate thickener face a huge challenge of slow settling and high overflow turbidity.To investigate the flocculation and settling performance and related mechanisms of the ore,this paper first conducts single-factor flocculation and settling tests on the sample,examining the effects of flocculant molecular weight,flocculant concentration,flocculant unit consumption,slurry concentration,and slurry pH value on its flocculation and settling behaviour using settling height and supernatant turbidity as indicators;furthermore,the sediment products are analyzed by Fourier Transform Infrared Spectroscopy to explore the adsorption mechanism between mineral particles and flocculants;finally,molecular dynamics simulation results are used to analyze the interaction between various minerals in the sample and flocculant molecules and water molecules.The physical results show that the optimal flocculation and settling effect of the sample is achieved when the anionic polyacrylamide(APAM)has a molecular weight of 10 million,a preparation concentration of 1.60‰,a unit consumption of 25 g/t,a slurry concentration of 25%,and a slurry pH=11;the infrared spectroscopy analysis indicates that hydrogen bonding and chemical adsorption occur between APAM and the mineral surface;the molecular dynamics results reveal that the flocculation adsorption of APAM on the four main minerals is a spontaneous process,and the APAM molecules are closely distributed on the surfaces of the four minerals,while water molecules mainly distribute on the surfaces of chalcopyrite and molybdenite.The research results can provide a scientific basis for the flocculation and settling process of fine particles copper-molybdenum mixed concentrate and the design and development of new flocculant molecules.