几种低温快烧陶瓷原料

本文简要论述了陶瓷原料中适合低温快烧的几种原料——叶蜡石、硅灰石、透辉石、透闪石、霞石正长岩和锂辉石。     

锂辉石对堇青石多孔陶瓷性能的影响

通过堇青石颗粒料制得的堇青石多孔陶瓷,与加入一定比例锂辉石制得的堇青石多孔陶瓷,在不同的温度下烧成,对气孔率、抗折强度、热膨胀系数等性能进行测试对比研究,对比实验数据表明加入锂辉石对堇青石多孔陶瓷的性能起到了优化作用。结果表明加入5%锂辉石烧成温度1280℃制得堇青石多孔陶瓷气孔率45.83%、抗折强度22.64MPa、热膨胀系数1.73×10-6/℃。     

Improved electrical and thermal properties of silicon oxycarbide/spodumene composites

Novel bulk SiOC/spodumene composites have been developed by spark plasma sintering (SPS) at relatively low temperature (1200–1400 °C). Spodumene is a cheap and natural available lithium aluminosilicate mineral which acts as meltable/active filler. At 1300–1400 °C, the Al migrates toward the glassy matrix producing a Si-Al-O network and the crystallization of α-cristobalite. The C_free phase also experiences a deep transformation. The epitaxial growth of few-layered graphene over SiC particles occurs at 1400 °C. An increase in the phonon transport is observed (36%, 1.28 – 2.14 Wm⁻¹K⁻¹) associated to the reduction of the interface resistance between the partially crystallized SiO₂ matrix and the SiC nano-wires/graphene-like carbon conductive phase. The electrical conductivity increases (1.14 ×10⁻² – 8.1 Sm⁻¹) due to the densification reached and an increasing ordering degree of the tortuous C_free phase with a high quality of interconnection and crystallization. Raman parameters are determinant to understand the thermal and electrical response.     

某复杂难选低品位锂辉石矿综合回收工艺

根据矿石性质研究某锂辉石矿产资源高效综合利用的工艺流程。采用硫酸作pH调整剂,十二胺作捕收剂优先浮选云母,以NaOH作调整剂、CaCl2作活化剂,油酸作捕收剂浮选锂辉石矿物,浮选粗精矿经再磨后以Na2CO3为调整剂精选,获得含Li2O 6.04%、回收率76.77%的锂辉石精矿和纯度较高的云母精矿。     

Insights into the floatability between spodumene and albite from crystal chemistry standpoint

Spodumene is a silicate mineral rich in lithium. However, the gangue mineral, albite has similar crystal chemical structure and composition to spodumene. In this work, the density functional theory (DFT) calculation was taken to research the floatability from the perspective of crystal chemistry. And contact angle test and reagent adsorption test were used to support the simulation results. In addition, the weighted total density of broken bonds is proposed for the first time to judge the generation probability of cleavage surface. The DFT calculation results display that the Na and Al sites on the albite surface are the adsorption sites of water molecules. While the water molecules only bond with Al atom on the surface of spodumene and each Al site can adsorb only one water molecule. Thus, the wetting effect of water molecules on the albite surface is stronger than that of spodumene. This is consistent with the result of contact angle. In sodium oleate system, the oleic acid anion is adsorbed on the spodumene surface in form of a multicomponent ring while the albite is a single ring. Theoretically, oleic acid anion can be strongly adsorbed on the surface of spodumene and albite under vacuum. The adsorption strength of spodumene is higher than that of albite. However, on hydrated surface, the adsorption strength of oleic acid anion on mineral surface is greatly reduced due to the interaction between water molecules and metal site on mineral surface. Thus, spodumene and albite are hard to float without external activated ions in sodium oleate system.