Fundamental Research On The Selective Depression Of Minerals Containing Calcium And Magnesium In Zinc Sulfide Ore Flotation

Dolomite is the main gangue mineral of carbonate host(MVT type)lead-zinc deposit.Dolomite entering the concentrate in flotation causes the increase of magnesium oxide,which has a serious negative impact on the subsequent smelting process.The reduction of magnesium is an important technical problem in sulfide ore flotation.This paper studies the selective depression of calcium and magnesium minerals in zinc sulfide flotation,which has important theoretical guiding significance for the effective recovery of zinc resources and other metal resources in China.Taking sphalerite and dolomite as the research object,this paper deeply studies the influence of different metal ions on the floatability of sphalerite and dolomite,and discusses the depression behavior of sodium alginate in the presence of copper ions.The mechanism of the depressant was studied by single mineral flotation,contact angle measurement,infrared spectroscopy analysis,X-ray photoelectron spectroscopy analysis,Zeta potential measurement and adsorbancy measurement.(1)The single mineral flotation results show that under the same flotation reagent system,the flotation recovery rate of-0.038 mm dolomite is significantly higher than that of-0.074+0.038 mm.Among copper,calcium and magnesium ions,copper ions have the greatest effect on mineral flotation behavior.The four depressants both have inhibitory effects on dolomite and sphalerite.Among them,the inhibitory effects sequence from high to low is: sodium alginate(SA),polyacrylic acid(PAA),citric acid(CA),ethylene diamine tetraacetic acid(EDTA).Although the addition of copper ion will slightly weaken the depression of sodium alginate on dolomite,it can "shield" the depression of depressants on sphalerite,so as to realize the flotation separation of sphalerite and dolomite.(2)Since sodium alginate has a large number of carboxyl and hydroxyl groups,adsorption on the surface of dolomite and sphalerite can enhance the hydrophilicity of the mineral surface,and greatly affect the electrical properties of the mineral surface,making the surface with a large number of negative electricity,enhance the electrostatic repulsion between particles,ease the mutual cohesion of the two.In the presence of copper ions,the adsorption capacity of sodium alginate and butyl xanthate on the surface of dolomite changed little,but the adsorption capacity of sodium alginate on the surface of sphalerite decreased,while the adsorption capacity of butyl xanthate increased significantly.Therefore,the floatability of sphalerite is restored and dolomite is depressed.(3)A zinc concentrate with zinc grade of 50.74%,recovery of 94.00%and magnesium content of 2.37% can be obtained by the closed-circuit flotation process of one roughing,two concentration and two scavenging for zinc sulfide ore with zinc grade of 3.06% and magnesium content of 8.90%.