钙硅比对铅锌尾矿微晶玻璃性能及重金属浸出毒性的影响

The Effect of CaO/SiO2Ratio on the Glass-ceramics Properties and Heavy Metal Leaching Ability of Lead-zinc Tailings

为用铅锌尾矿合成微晶玻璃,研究了钙硅比(mCaO/mSiO2)对基础玻璃析晶温度、微晶玻璃结构、性能的影响,并采用TCLP法研究了其对重金属浸出毒性的影响。结果表明,随着钙硅比增大,基础玻璃的玻璃化转变温度和结晶温度先降后升。微晶玻璃的主要晶相为钠长石,钙硅比的增加阻碍了钠长石的晶体生长,但有利于透辉石、钙铝黄长石和霞石晶体的形成。当比值为0.45时,微晶玻璃的综合性能最好:此时铅锌尾矿掺入量为70.86%,密度为2.93g/cm3,抗压强度为182.64MPa,在酸性溶液中失重为2.26%,在碱性溶液中失重为1.65%。浸出试验表明,锌、锰、铅的浸出随钙硅比升高的变化不具有相似性,微晶玻璃对铅固化效果最差。

In this study,glass ceramics were synthesized from lead-zinc tailings.The effect of CaO/SiO2 ratio on the crystallization temperature of basic glass,the structure and the properties of glass ceramics was studied.And the heavy metal leaching ability of glass ceramics was explored by TCLP method.The results show that the transition temperature and crystallization temperature of basic glass first decrease and then increase with the increase of CaO/SiO2 ratio.The main crystalline phase of the glass ceramics is albite.The increase of CaO/SiO2 ratio hindered the crystal growth of albite,but facilitated the formation of diopside,gehlenite and nepheline crystals.When the CaO/SiO2 ratio is 0.45,the glass-ceramic samples obtain the best comprehensive property.By now,the mixing amount of lead-zinc tailings is 70.86%,density is 2.93 g/cm3,compressive strength is 178.85 MPa,as well as weight loss is 2.12%in acidic solution and 1.57%in alkali solution.The leaching experiments show that the leaching of Zn,Mn and Pb has no similarity with the increase of CaO/SiO2 ratio,and the lead curing effect of glass ceramics is the poorest.