Study On Composition Analysis And Chemical Agglomeration Of Dust Particles In Non-ferrous Smelting

The particles produced in non-ferrous smelting process are characterized by small size and high heavy metal content.If not properly treated,they will pose a serious threat to the ecological environment and human health.For non-ferrous smelting dust particle composition complex,hierarchical feature is unknown,lack of strengthened recycling method,and such problems,this study analyzes the physical and chemical properties,classification characteristics of nonferrous smelting dust particles,the chemical agglomeration solutions suitable for non-ferrous smelting particles was screened out,which helps to improve the recovery efficiency of valuable elements.The main conclusions of this paper are as follows:（1）The physical and chemical characteristics of dust particles in typical non-ferrous smelting were studied.The content of valuable metals in dust particles from lead smelting sintering is close to 60%,and the content of valuable metals in dust particles from copper flash smelting is more than 35%,which has great recovery potential,Pb in these particles mainly exists in the form of lead sulfate.The toxic leaching experiment shows that the leaching concentration of Pb,Zn and Cd of particles in lead smelting dust setting chamber dust（DSCD）is higher than the concentration limit,and the leaching concentration of Zn,Cd and As of dust particles in electrostatic precipitator dust（ESPD）is higher than the concentration limit.The leaching concentration of As,Cu,Pb and Zn of particles in copper smelting waste heat boiler dust（WHBD）,DSCD and ESPD exceeds the concentration limit.Therefore,strengthening the recovery of dust particles in non-ferrous smelting has economic and environmental benefits.（2）The characteristics of mass and element distribution by particle size in dust particle from lead smelting and copper smelting were revealed.The peak values of mass-particle size distribution in DSCD particles and ESPD particles of lead smelting were 5.38μm and 3.66μm,respectively.Pb has the highest concentration in PM1-2.5,the concentration of Zn in submicron particles is larger than that in super-micron particles,while the concentration of Cd has an opposite trend,As has the highest concentration in PM2.5-10.The peak value of mss-particle size distribution in copper smelting WHBD particles,DSCD particles and ESPD particles is 5.38μm.The peak values of element concentration-particle size distribution in WHBD particles are 0.0537μm and 0.257μm,while the peak values of element concentration-particle size distribution in DSCD particles are shifted to 0.0942μm and 0.383μm,the relationship between element concentration and particle size of ESPD particles is not obvious.（3）The effects of polymer,surfactant,p H and(NH₄2)SO₄ on the chemical agglomeration of lead sulfate particles were investigated(the median particle size(D₅₀)of untreated lead sulfate particles was 7.778μm,and the particle proportion of diameter less than 10μm was 67.92%).Agglomeration effect of polymer on lead sulfate particles:Polyacrylamide（PAM）>Xanthan gum（XTG）>Polyferric sulfate（PFS）>Polyaluminum chloride（PAC）,and the higher the polymer concentration,the better the agglomeration effect.Anionic surfactants can promote the agglomeration of the four polymers.The composite solution of XTG and sodium dodecyl sulfate（SDS）has a better agglomeration effect in neutral environment.The composite solution of PAM and SDS has a better agglomeration effect in alkaline environment,when the p H of this composite solution is 11,the D₅₀of lead sulfate particles increases to 27.346μm,the particle proportion of diameter less than 10μm was reduced by 53.38%.Appropriate concentration of(NH₄2)SO₄ can promote the agglomeration effect of inorganic agglomeration system on lead sulfate particles.When treated with 1%PAC+0.25%SDS+3%(NH₄2)SO₄,lead sulfate particle D₅₀increased to 27.784μm,and the particle proportion of diameter less than10μm was reduced by 54.97%.When treated with 1%PFS,0.25%SDS and1%（NH₄）₂SO₄,the lead sulfate particle D₅₀ was increased to 24.083μm,and the particle proportion of diameter less than 10μm was reduced by 53.52%52 figures,16 tables and 97 references...