利用含铬污泥制备微晶玻璃关键技术开发

开发了冷轧含铬污泥中温脱硫保铬预处理工艺以及利用含铬污泥制备CaO-MgO-Al2O3-SiO2(CMAS)系统微晶玻璃的工艺,研究了晶核剂对微晶玻璃的物相、显微结构及性能的影响。所开发的工艺过程清洁环保,制品力学性能好、无浸出毒性。本技术不但实现了含铬污泥无害化处理,还发挥了污泥的资源价值,为冷轧含铬污泥的厂内安全低成本处置提供了技术解决方案。     

一种利用金矿尾矿制备Ca-α-SiAION材料的方法

该专利公开了一种利用金矿尾矿制备Ca—α-SiAION材料的方法。该工艺为：粉碎、配料、混合球磨、干燥制样、烧结和去除残留碳元素,最终得到主晶相为Ca—α—SiAION,次晶相为SiC的陶瓷粉体。该方法得到的Ca—α—SiAION陶瓷粉体纯度较高,可广泛应用于冶金、化工、电力、能源等工业领域,且工艺操作简单,成本低,对实现尾矿的综合利用有很重要的意义。     

综合利用黄磷熔渣和尾气生产微晶玻璃的方法

该发明公开了一种综合利用黄磷熔渣和尾气生产微晶玻璃的方法。其方法为：将温度为1450～1500℃的黄磷熔融炉渣加入熔融炉中,同时进行炉前快速分析,使物料组分（质量分数）符合SiO2 50％～60％、A12036％～7％、CaO 22％～30％、     

打开沉睡的资源宝库——访中国地质科学院尾矿利用技术中心首任主任李章大教授

据国土资源部提供的信息,我国现有尾矿库12 718座,其中在建尾矿库1 526座,占总数的12%,已经闭库的尾矿库1 024座,占总数的8%,目前,全国尾矿堆积总量约为80.46亿t。仅2007年,全国尾矿排量近10亿t。尾矿的大量堆存带来资源、环境、安全和土地等诸多问题。随着我国循环经济发展战略的提出,决策部门已经意识到这些被丢弃的"固体废物"价值巨大,无异于一座矿产资源宝库。本刊就发展循环经济、加强尾矿利用等问题对中国地质科学院尾矿利用技术中心首任主任李章大教授进行了访问。     

Study on the mechanical and environmental properties of concrete containing cathode ray tube glass aggregate

Cathode ray tube (CRT) glass is considered a hazardous material due to its lead toxicity. In addition, current disposal practices are being phased out due to their adverse environmental impacts. In this project, CRT glass was used as a fine aggregate replacement in concrete. Life-cycle material characterization was conducted by evaluating the durability and strength of the CRT-Concrete. Leaching tests were also conducted to investigate whether the material meets drinking water limits for Pb. Test results show that the plastic state of the CRT-Concrete was affected by the angularity of the glass particles. Moreover, the compressive strength of CRT-Concrete met and exceeded that of the control specimen. However, CRT-Concrete was susceptible to expansive alkali-silica reactions when more than 10% CRT replacement was used. Environmental leaching results show that lead concentrations from CRT-Concrete are below the drinking water limits depending on the CRT volume replacement and if biopolymers are used.     

Energy-efficient modification of reduction-melting for lead recovery from cathode ray tube funnel glass

Lead can be recovered from funnel glass of waste cathode ray tubes via reduction melting. While low-temperature melting is necessary for reduced energy consumption, previously proposed methods required high melting temperatures (1400 °C) for the reduction melting. In this study, the reduction melting of the funnel glass was performed at 900–1000 °C using a lab-scale reactor with varying concentrations of Na₂CO₃ at different melting temperatures and melting times. The optimum Na₂CO₃ dosage and melting temperature for efficient lead recovery was 0.5 g per 1 g of the funnel glass and 1000 °C respectively. By the reduction melting with the mentioned conditions, 92% of the lead in the funnel glass was recovered in 60 min. However, further lead recovery was difficult because the rate of the lead recovery decreased as with the recovery of increasing quantity of the lead from the glass. Thus, the lead remaining in the glass after the reduction melting was extracted with 1 M HCl, and the lead recovery improved to 98%.     

Recovery of yttrium from fluorescent powder of cathode ray tube,CRT: Zn removal by sulphide precipitation

This work is focused on the recovery of yttrium and zinc from fluorescent powder of cathode ray tube (CRT). Metals are extracted by sulphuric acid in the presence of hydrogen peroxide. Leaching tests are carried out according to a 2² full factorial plan and the highest extraction yields for yttrium and zinc equal to 100% are observed under the following conditions: 3 M of sulphuric acid, 10% v/v of H₂O₂ concentrated solution at 30% v/v, 10% w/w pulp density, 70 °C and 3 h of reaction.Two series of precipitation tests for zinc are carried out: a 2² full factorial design and a completely randomized factorial design. In these series the factors investigated are pH of solution during the precipitation and the amount of sodium sulphide added to precipitate zinc sulphide. The data of these tests are used to describe two empirical mathematical models for zinc and yttrium precipitation yields by regression analysis. The highest precipitation yields for zinc are obtained under the following conditions: pH equal to 2–2.5% and 10–12% v/v of Na₂S concentrated solution at 10% w/v. In these conditions the coprecipitation of yttrium is of 15–20%.Finally further yttrium precipitation experiments by oxalic acid on the residual solutions, after removing of zinc, show that yttrium could be recovered and calcined to obtain the final product as yttrium oxide. The achieved results allow to propose a CRT recycling process based on leaching of fluorescent powder from cathode ray tube and recovery of yttrium oxide after removing of zinc by precipitation. The final recovery of yttrium is 75–80%.