| Heavy metal pollution is one of the most concerned environmental issues in the world.Non-ferrous metal smelting contributes an important anthropogenic source of heavy metal emissions,the classification list and attributes of solid waste in the non-ferrous metal smelting industry are not well documented,and thus is urgent to supplement the relating knowledge.This could improve our understandings of solid waste treatment,disposal and resource utilization,and also facilitate the relevant standard setting and technical specifications in the non-ferrous metal smelting industry.This study taked bulk solid waste in the non-ferrous metal smelting industry as the research object,systematically analyzed the key production and waste nodes in the production process of Cu,Pb,Zn and Al products,clarified the categories of solid waste with similar source characteristics,and constructed classification methods and lists that characterized common characteristics of non-ferrous smelting solid waste.On this basis,tested and analyzed the physical,chemical,visualization and pollutant indicators of common source solid waste,and obtained the characteristics of solid waste resources and environmental attributes.The main conclusions were as follows:（1）The classification method and list of common sources of solid wastes in the non-ferrous metal smelting industry were constructed.Among them,this method clarified the categories of non-ferrous smelting solid wastes with similar source characteristics（such as smelting waste residue,dust,waste acid,waste activated carbon,waste catalyst and sludge,etc.）,and divided the source into units of crushing batching,smelting reaction,purification and recovery,dust collection and purification,sewage acid treatment,acid-making desulfurization and reclaimed water treatment.The classification list is based on these 7 major units to classify 115 kinds of non-ferrous smelting solid wastes.It compared with the National List of Hazardous Wastes,this list refined the process description,narrows the scope of definition,and classifies the waste types by quality.It had certainty,practicality and feasibility.（2）The detection results of the physical indicators of the non-ferrous smelting solid wastes of each common unit and the corresponding resource attribute characterization were discriminated.Among them,the water content changes of crushing batching,smelting reaction,purification and recovery,dust collection and purification,sewage acid treatment,acid-making desulfurization and reclaimed water treatment unit wastes were 0.193%～0.234%,0.019%～25.6%,0.039%～3.96%,0.238%～2.69%,8.67%～52.9%,28.9%～31.1%and 50.3%～68.4%,so the water content of the first four units were low,and the last three units were high.At the same time,the p H change range was 10.98～11.14（alkaline）,3.57～9.48（acid partial neutral）,5.79～13.4（neutral partial alkaline）,1.85～11.5（acid or alkaline）,0.59～13.5（strong acid Strong alkaline）,13.6～13.8（strong alkaline）and 9.02～9.21（alkaline）,so the waste of units in crushing batching,smelting reaction and reclaimed water treatment were non-corrosive,and the wastes of other units were corrosive.（3）Identified the chemical index detection results of the non-ferrous smelting solid wastes of each common unit and their corresponding resource attribute characterization.Among them,the wastes of the crushing batching unit were composed of flocculent powder,with a spinel phase and a corundum phase,and the main components were Al2O3（68.4%～70.8%）and Mg O（9.12%～10.4%）;the wastes in the smelting reaction unit were composed of slab-like particles,in the form of fayalite phase and arsenite copper phase,and the main components were Fe2O3（24.3%-66.0%）and As2O3（1.49%-46.1%）;the wastes of the purification and recovery unit were composed of spherical particles,which are corundum phase and lead yellow phase,and the main components were Al2O3（37.1%～84.0%）and Pb O（0.158%～98.8%）;the wastes in the dust collection and purification unit were composed of dusty powder,which is in the form of lead alum and red zinc ore,and the main components were Zn O（0.134%～72.4%）and Pb O（0.015%～71.3%）;the wastes in the sewage acid treatment unit were composed of sludge particles,which were lead alum phase and white arsenite phase,and the main components were Pb O（0.223%～94.1%）and As2O3（0.487%～68.8%）;the wastes of the acid-making desulfurization unit were composed of fine powder,in the form of gypsum,and the main components were Ca O（43.2%～47.5%）and Si O2（0.626%～0.652%）;the wastes in the reclaimed water treatment unit were composed of massive particles in the calcite phase,and the main components were Fe2O3（12.5%～46.4%）and Ca O（5.37%～27.2%）.The main elements of non-ferrous smelting solid waste were Al,Fe,As,Pb,Zn,Ca,Si,etc.And existed in the form of oxides,silicates,aluminates and sulfates.If they replace the traditional preparation raw materials of new building materials,they can effectively expand the resource utilization of industrial solid waste and reduce the probability of hazards.（4）The test results of the visual indicators of the non-ferrous smelting solid wastes in each common unit and their corresponding environmental attribute characterization were clarified.Among them,the wastes of the crushing batching unit were a gray powder dust ash without irritating odor;the wastes of the smelting reaction unit were black ash or black-red smelting waste slag without irritating odor;the wastes in the purification and recovery unit were gray-white or yellow or black granular recovery by-products without irritating odor;the wastes in the dust collection and purification unit were white or brown or black powder-like dust-collecting soot without irritating odor;the wastes of the sewage acid treatment unit were a brown-red or black lump of waste acid treatment with a pungent odor;the wastes of the acid-making desulfurization unit were a gray powder desulfurization by-product without a pungent odor;the wastes of the reclaimed water treatment unit were a dark red massive water treatment sludge with an irritating smell.（5）The test results of the pollutant indicators of the non-ferrous smelting solid wastes in each common unit and their corresponding environmental properties were revealed.Among them,units of crushing batching,smelting reaction,purification and recovery,dust collection and purification,sewage acid treatment,acid-making desulfurization and reclaimed water treatment of content and leaching toxicity concentration of the primary heavy metals were Cu（894±14.0 mg/kg and 0.355mg/L）,Zn（35309±1724 mg/kg and 3141mg/L）,Zn（36277±854 mg/kg and13035mg/L）,Zn（34404±135 mg/kg and 1684mg/L）,As（9055±619 mg/kg and2637mg/L）,Cu（75.3±4.27 mg/kg and 4.45mg/L）and As（861±4.91 mg/kg and0.476mg/L）.At the same time,the leaching concentration in the wastes of crushing ingredients and acid-making desulfurization units were lower than the limit value of China’s GB 5085.3-2007 standard but exceeded the limit value of Class III standard of GB/T 14848-2017,and the leaching concentration of the remaining five units of wastes were higher than the two types of standard limits.Since the hazards of solid waste mainly depend on the concentration of the pollutants they release,the environmental risks brought by Cu,Zn,and As should be focused on.This study built a classification list of common sources of non-ferrous smelting solid waste.And explored the physical,chemical,visualization and pollutant indicators intervals or statistical values of non-ferrous smelting solid wastes with common sources.The results showed that the resource and environmental attributes of non-ferrous metallurgical solid waste of unknown origin can be gradually identified through the four indicators.Therefore,this research provided theoretical basis and rational suggestions for the treatment and disposal of nonferrous smelting solid waste and the process of resource utilization,which had certain scientific and practical significance. |
