Leaching Identity Studies On Cinder Of Sulphuric Acid Production

Sulfuric acid is an important basic chemical raw materials, which widelyused in the petrochemical, chemical, steel, metallurgy, military and manyother fields. China’s sulphuric acid produces nearly10million tons wasteevery year, accounting for about1/3chemicalwaste. In the present enterprise,such waste little part is used for making bricks and cement additives, littlepart is used for selecting iron, most of the waste is disposed in stacked in theopen air, not only takes up a lot of land, but also exist with different content ofCu, Cd, Pb, Zn, Ni, Cr and As and other heavy metals because of the acidsource of raw materials and production process of the differences, which arerich in heavy metal waste residue in nature and in a variety of liquid solidphase after exposure, the harmful ingredients will be dissolved into the liquidphase, the formation contains heavy metal leaching liquid. If the leachingsolution of toxic substances goes into the environment, it will directly causethe soil and groundwater pollution. For the production of sulfuric acid slagtype ascription, at present both our country and abroad have no systematicresearch reports. This article takes four large-scale sulphuric acid productionenterprises cinder samples of the Hubei Province as the research object,adopts the horizontal vibration method, nitric acid, acetic acid buffer solutionmethod three kinds of different leaching method for extracting residue ofheavy metals, to study the leaching rules, to understand the different heavymetals in different extracting method of leaching characteristics difference.This paper obtained the following conclusions:(1) Study on the production of sulfuric acid slag and belongs to the solidwaste category, and is not included in the "national hazardous waste list".(2) The harmful element leaching results:Leaching solution of Cu, Cd, Pb, Zn, Ni, Cr and As content fluctuationrange is larger, which may be associated with acid raw materials, technologyand raw materials sources related to the different. Leaching method and particle diameter on As, total Cr, Ni, Cd, Zn, Pb, Cd leaching has certaineffect. Overall, the smaller the particle size, leaching solution leachingamount of harmful elements.(3) Slag leaching toxicity conclusion: To sulfur fine sand cinder, YFsulfur fine sand cinder1, YF sulfur fine sand cinder2, auspicious clouds pyriteslag and pyrite cinder iron separation of auspicious clouds residue in Ascontent than the leaching toxicity concentration limits, exceed the standardmultiples are respectively0.146,0.398,0.718,0.29,0.242times; to sulfur finesand cinder Pb content than the leaching toxicity concentration limits, exceedthe standard ratio of0.166times; to pyrite cinder, YH sulfur fine sand cinder,YF sulfur fine sand cinder1, YF sulfur fine sand cinder2Cd content than theleaching toxicity concentration limits, exceed the standard multiples ofrespectively0.24,2.02,0.02,0.46times. In the sample, only the HML sulfurfine sand cinder all harmful elements (As, Cr, Ni, Cu, Zn, Pb, Cd) does notexceed the leaching toxicity concentration limit, but Cr, Ni, other harmfulelements (As, Cu, Zn, Pb, Cd) beyond the integrated wastewater dischargestandard concentration limit. It is judged to pyrite cinder, YH sulfur fine sandcinder, YF sulfur fine sand cinder1, YF sulfur fine sand cinder2, auspiciousclouds pyrite slag and pyrite cinder iron separation of auspicious cloudsresidue with leaching toxicity of hazardous waste, HML sulfur fine sandcinder as having no leaching toxicity of hazardous waste, but because of theharmful elements As, Cu, Zn, Pb, Cd beyond the integrated wastewaterdischarge standard of concentration limits, it is further judged HML sulfurfine sand cinder as class II general solid waste.For sulfuric acid production process cinder, should be in accordance withthe hazardous waste management requirements for disposal, referring to"standard for pollution control on hazardous waste"(GB18597-2001) and"pollution control standard for hazardous waste landfill"(GB18598-2001),avoid" two pollution". In addition, it is recommended to have a more in-depth study, thus the optimal disposal of waste.