某低品位伟晶岩型锂辉石选矿试验

为降低某低品位伟晶岩型锂辉石选矿生产成本,采用重介质分选工艺,预测可抛弃近70%的粗粒尾矿,可获得Li₂O品位为5.25%,Li₂O回收率为63.70%的锂辉石精矿。为提高其选矿回收率,采用研发的捕收剂EL进行了浮选试验研究,试验可获得Li₂O品位为4.12%,Li₂O回收率为80.76%的锂辉石精矿。精选抛尾工艺流程可在一定程度上消除矿泥对精选的影响,同时减少金属量在矿泥中的损失,该研究成果对选矿厂技术改造具有一定的指导意义。     

碳酸钠和氢氧化钠对锂辉石矿浮选的影响

以四川呷基卡锂矿为研究对象,采用浮选工艺分选锂辉石,主要研究了调整剂碳酸钠和氢氧化钠添加次序、作用时间与用量对浮选指标的影响。发现先添加碳酸钠后添加氢氧化钠,可大幅提高锂精矿的Li₂O品位;适当延长氢氧化钠的作用时间,可有效提升锂精矿Li₂O的回收率;高用量的碳酸钠会抑制锂辉石的上浮,高用量的氢氧化钠则会降低捕收剂对锂辉石的选择性。矿石经2粗3精1扫闭路试验,可获得Li₂O品位和回收率分别为4.48%和87.76%的锂精矿。     

锂辉石的工业应用

作为锂最主要来源的工业矿石－锂辉石在陶瓷、冶金、搪瓷、特种玻璃、化工等方面的应用迅速发展并日益扩大，本文着重介绍了锂辉石在陶瓷工业的应用，在其他领域的应用也涉及到。阐明在制品中添加锂辉石，能降低烧成温度，提高机械强度，抗热振性以及具有良好的化学稳定性的原因。     

Selective flotation separation of spodumene from feldspar using new mixed anionic/cationic collectors

The selectivity in flotation separation of spodumene from other pegmatic aluminosilicates such as feldspar and mica, using a single fatty acid anionic collector, is found to be very difficult. It is attributed to the same surface Al site for interaction with fatty acid. In this study, a collector mixture of sodium oleate (NaOL) and dodecyl trimethyl ammonium chloride (DTAC) demonstrates a high selectivity for the flotation of spodumene from feldspar. The influences of important factors such as molar ratio of the mixed collectors, dosages of calcium chloride, sodium hydroxide and sodium carbonate, and pulp temperature on spodumene and feldspar flotation using the mixed collectors have been investigated through micro-flotation tests. The optimum molar ratio of NaOL and DTAC is found to be 9:1. Sodium hydroxide has to be used as a pH regulator. Without the use of depressants, no selectivity is observed as the flotation of spodumene and feldspar are activated by Ca²⁺. Sodium carbonate must be used as depressant of feldspar. A comparison of the flotation for a lithium pegmatite ore using mixed fatty acid soaps and mixed anionic/cationic collectors (NaOL/DTAC) was carried out by the batch flotation tests. The results indicated that NaOL/DTAC decrease collector consumption by two-thirds. The recovery and grade of Li₂O concentrates increase by 4.93% and 0.31%, respectively.     

Low Li2O content study in Li2O-Al2O3-SiO2 glass-ceramics

The price of lithium-containing minerals and other chemical materials continues to increase, resulting in an increase in the production cost of Li₂O-Al₂O₃-SiO₂ (LAS) system glass-ceramics. In the LAS glass-ceramics component, the reduction in the amount of Li₂O used can reduce the cost of the product. It is worthwhile to study whether it is possible to prepare glass-ceramics with low expansion properties under low Li₂O content. The effect of Li₂O content on the glass-ceramics of LAS system was studied. In this paper, spodumene was used as the main raw material, and TiO₂ and ZrO₂ were added as crystal nucleating agents to prepare transparent glass-ceramics with low expansion coefficient. The effects of the change of Li₂O content on the crystal phase and microstructure of glass-ceramics were investigated by XRD, DSC, FTIR and SEM. The results show that the main crystalline phase of the low expansion transparent glass-ceramics is β-quartz solid solution. When Li₂O content is in the range of 2.99 wt% to 4.13 wt%, low expansion glass ceramics can be prepared by an appropriate method. With the increase of Li₂O content, the average coefficient of thermal expansion (CTE) in the temperature range of 30 °C–300 °C shows a decreasing trend. When Li₂O content is in the range of 3.51 wt% to 4.13 wt%, the thermal expansion coefficient of the glass ceramics is extremely small, and even a negative expansion coefficient occurs.     

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/℃。     

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。     

Preparation and thermal shock resistance of cordierite-spodumene composite ceramics for solar heat transmission pipeline

Cordierite-spodumene composite ceramics with 5, 10, 15 wt% spodumene used for solar heat transmission pipeline were in-situ prepared via pressureless sintering from kaolin, talc, γ-Al₂O₃ and spodumene. Effects of spodumene on densification, mechanical properties, thermal shock resistance, phase composition and microstructure of the composite ceramics were investigated. The results showed that spodumene used as flux material decreased the sintering temperature greatly by 40–80 °C, and improved densification and mechanical properties of the composite ceramics. Especially, sample A3 with 10 wt% spodumene additive sintered at 1380 °C exhibited the best bending strength and thermal shock resistance. The bending strengths of A3 before and after 30 thermal shock cycles (wind cooling from 1100 °C to room temperature) were 102.88 MPa and 96.29 MPa, respectively. XRD analysis indicated that the main phases of the samples before 30 thermal shock cycles were α-cordierite, α-quartz and MgAl₂O₄, and plenty of β-spodumene appeared after thermal shock. SEM micrographs illustrated that the submicron β-spodumene grains generated at the grain boundaries after thermal shock improved the thermal shock resistance. It is believed that the cordierite-spodumene composite ceramics can be a promising candidate material for heat transmission pipeline in the solar thermal power generation.     

锂辉石的成矿及在陶瓷和玻璃工业中的应用

锂辉石为典型的伟晶岩矿物，主要生成于花岗伟晶岩脉中。由地其独特的化学性质，使之在陶瓷和玻璃工业中的应用越来越普遍。并以其熔剂效应强，膨胀系数低，而提高烷融效果及显著改善制品的热稳定性，化学稳定性和机械性能。     

Theoretical analysis of optical characteristics of the alpha spodumene in ultraviolet region

It is presented an analysis of some important optical characteristics of the natural spodumene crystal, based on the first-principles calculations of its electronic structure and complex dielectric tensor. The optical absorption spectrum is interpreted in terms of electronic band structure for incident radiation energy up to 35 eV. The orientation of the three orthogonal principal optical axes is determined relative to the crystallographic axes, and expressed as function of the incident radiation wavelength. Reflectivity and electron energy loss are calculated along the three principal axes. All calculated optical properties are found to be highly anisotropic.