利用碱渣和金尾矿协同制备多孔陶瓷中孔结构和晶相的影响因素研究

以双固废(金尾矿和碱渣)制备的保温型泡沫陶瓷为基础,考察了温度、发泡剂、助熔剂、稳泡剂的含量对Ca-Mg-Al-Si体系多孔陶瓷孔结构和晶相的影响,采用Image-Pro Plus 6.0软件对多孔产品的孔径分布进行了统计学分析,讨论了烧结过程中原料基本组成对微观结构的影响。研究发现:升高温度,会破坏硅酸盐聚合度,改变非晶态物质含量,通过影响熔体黏度改变孔结构;发泡剂SiC对孔结构的调节主要通过改变添加量来控制孔内气体压力P_(g),从而调节孔结构;Al对孔结构的影响存在两面性,当Al含量低时(n Al_(2)O_(3)/n_(MO)<1,M=Ca,Mg,K,Na),Al—O配位体为四面体,当Al含量高(_(nAl _(2)O _(3))/n_(MO)>1)时,Al—O配位体为八面体,配位变化会引起黏度的复杂变化;Ca对孔结构的影响分两个阶段,Ca含量低时,主要参与打破硅酸盐网络结构,Ca含量高时,其参与生成少量辉石晶体;Mg通过生成辉石晶体,对孔结构进行调控,但Mg含量过高时,生成的大量针状晶体会对气孔产生过度抑制,导致气孔不能正常发育。

Preparation of Thermal Insulation Ceramics Using Felsic Tailings as Main Raw Material and Soda-ash Dregs as Flux

Low-cost thermal insulation porous ceramics with uniform pore diameter and low bulk density were prepared with soda-ash dregs and felsic tailings.We investigated the effect of temperature,foaming agent,fluxing agent,Al_(2)O_(3)and CaO content on the pore structure and crystal phase of porous ceramics.The effect of Ca^(2+)in soda-ash dregs on the preparation of quartz-feldspar based porous ceramics was studied.The results showed that the contribution of Ca^(2+)to the preparation of porous ceramics in this system was mainly to accelerate the Si-O bond fracture and reduce the sintering temperature at the initial stage of sintering,which destroyed the needle-like feldspar in the high temperature melt and reduced the melt viscosity,thus reduced the foaming resistance and promoted the porous products with uniform pore size distribution.The Ca^(2+)content on the high side can participate in the formation of crystals in sintering.The generated needle-like diopside and augite,which have small length-diameter ratio,will negligibly change in the viscosity of melt at high temperatures,and their inhibition effect on pores is not as good as that of feldspar with large length-diameter ratio,resulting in the merger and collapse of pores.But the increase of diopside and augite can improve the compressive strength of porous products to some extent.Porous ceramic products containing needle-like feldspar phase can be prepared by using two kinds of solid waste,which can improve the compressive strength of the products and reduce the raw material cost and energy consumption while comprehensively utilizing the double solid waste.The optimal product has a bulk density of 0.45 g/cm^(3),a compressive strength of 3.17 MPa,and a thermal conductivity of 0.11 W/(m·K).

利用三山岛金矿尾矿制备塑料母料

经磨矿作业后,金矿选别过程通常会产生大量细粒尾矿,三山岛金矿尾矿堆存量较大,尾矿资源丰富。尾矿中有价元素含量不高,尾矿中丰富的非金属矿资源尚未得到有效回收利用。本文以三山岛金矿尾矿为主要原料,进行了有价元素回收探索研究、分级提纯研究、表面改性研究以及制备PP,PE母料添料的试验研究。将分级提纯后的尾矿作为碳酸钙替代料制备的PP,PE母料添料具有良好的性能指标,实现节能减排,减轻环境负担的同时,减少橡胶原料的消耗。