First-principle investigation on mechanism of Ca ion activating flotation of spodumene

Different hypotheses of the activation mechanisms of metallic ions for silicate minerals flotation were stated in this work. Spodumene and Ca ion were taken to illustrate this issue. Flotation test results and diagram of Ca ion species distribution vs pH show that the dominant hydrolyzed species are Ca（OH）？and Ca（OH）2, which is in correspondence with the maximum flotation recovery of spodumene. Density functional theory（DFT） calculation results reveal further that the precipitation of calcium hydroxide on spodumene surface is the effective process to activate the flotation of spodumene.     

矿物原料制备聚合氯化铝的研究进展

综述了利用高岭土、铝矾土、煤矸石等矿物原料制备聚合氯化铝的研究进展,简要分析了利用矿物原料制备聚合氯化铝普遍存在的问题,并对新的研究方向做了展望。     

块系覆岩中摆型波传播对巷道支护动力响应影响

为研究支护体自身的动力响应规律,通过理论和计算分析岩体中的非线性摆型波传播对巷道支护动力响应的影响,根据摆型波在非连续自应力块系上覆岩体中传播时的支护动力响应模型,研究上覆岩块间的黏弹性性质及岩块破坏对支护动力响应的影响。通过计算分析得出,上覆岩块间弹性下降时,支护的动态受拉和受压幅值随之下降且周期变大;上覆岩块间阻尼增大时,支护的受拉和受压周期不变,但周期内的微扰动逐渐消失且幅值略有下降;上覆岩块沿垂直冲击方向破裂成两个子块时,支护的受拉和受压次数增加。     

燃煤电厂软土层地基预处理方案和施工探究

本文阐述了预处理的重要性,揭示了当前施工中存在的问题,并对软土层地基处理提出了具体的方案。     

A new kinetic model for Ni(II) ion flotation based on gene expression programming

ABSTRACT

The Ni(II) ion flotation kinetics with sodium dodecylsulfate as collector was studied with the aim of developing new models to predict the flotation rate constant (k) of Ni(II) ions and water removal during the process of Ni(II) ion flotation. In this regard, the most influential parameters on Ni(II) ion flotation efficiency including the ratio of collector concentration on the Ni(II) ion concentration, impeller speed, activity coefficient, and pH were used to develop predictive models. The results show that the proposed gene expression programming models can be used to predict the flotation rate constant of Ni(II) ions and water removal.     

Flotation Selectivity of Phosphate Ore: Effects of Particle Size and Reagent Concentration

The flotation selectivity of apatite particles from a carbonatite complex was investigated in a flotation column as a function of particle size and reagent concentrations. Experiments were performed according to a factorial experimental design. Fine and coarse particles showed different sensitivities to variations in the concentration of the reagent. Coarser particles showed a higher selectivity ratio and greater sensitivity to the addition of different reagent dosages, providing a more selective separation and a better quality product. Finer particles presented lower selectivity ratios, reflecting the difficulty involved in the concentration process with this particle size.     

Integrated characteristics and performance of zero emission coal system

Before the commercialization of zero emission coal (ZEC), some technical hurdles must be settled and the performance of the whole system needs to be studied. The main technical hurdles of ZEC system are analyzed and some solutions are presented in this paper. A detailed ZEC system is setup and its characteristics are studied. High temperature solid oxide fuel cell (SOFC) is used to produce electricity and served as the heat source for the decarbonater. ZnO and NaHCO₃ are proposed to deeply eliminate H₂S and HCl. H₂ recycle ratio should be kept at 0.75 for the high conversion ratio of carbon in the gasifier and the high system efficiency. Calcium to carbon mole ratio (CTCR) should be kept around 0.6 to reach high CO₂ sequestration rate and acceptable economic penalty. Fuel utilization factor (U_f) of SOFC should be kept around 0.55 so as to supply enough heat to the decarbonater, and steam to carbon ratio (STCR) for the reformers in the system should be kept around 2.0. With these optimized parameters, the total efficiency of the system of 69.1% and the CO₂ sequestration ratio of 87% can be reached.     

水煤浆气化制氢的气化压力选择

为确定最适合水煤浆制氢装置的气化压力,以石油焦为原料,采用单喷嘴水煤浆气化技术,在20万m~3/h制氢规模下,对4.0和6.5 MPa两种不同气化压力下的装置配置、技术经济指标、消耗、投资进行综合对比。结果表明,4.0 MPa压力等级下的气化装置和净化装置均出现系列数增加或设备结构尺寸变大的情况,导致投资增加;系列数的增加还会导致备用率降低,在线率和装置可靠性下降,不利于连续稳定供氢;4.0 MPa压力等级低,装置消耗增加,尤其对于低温甲醇洗单元,冷量消耗将大幅增加。因此,针对20万m~3/h制氢规模,6.5 MPa气化压力下的装置在投资、消耗、占地、在线率、可靠性以及操作和维修的复杂性、生产成本等方面均优于4.0 MPa气化压力,在选择气化压力时应优先考虑6.5 MPa压力等级。     

松软突出煤层钻进困难的原因分析

在分析煤层深孔钻进困难原因的基础上，提出“钻穴”概念，分析了“钻穴”对钻进的影响。在分析“钻穴”类型及成因的基础上，建立“钻穴”内流体排渣模型，采用数学方法，分析钻孔深度和“钻穴”的关系。结果表明：在纯流体排渣情况下，松软、突出煤层的钻孔深度几乎与钻机动力大小无关，而取决于危害型“钻穴”的发生位置和“钻穴”的体积大小。基于对“钻穴”的新认识，提出流体与机械协同排渣的新观点，以此克服或减轻“钻穴”的危害，并发明了“双动力低螺旋钻杆”。     

天然气与煤粉混烧技术在工业锅炉上的应用

介绍了在链条炉的基础上,以煤粉、天然气的悬浮燃烧方式配合火床燃烧的节能改造技术,对一台20t/h快装链条炉改造后,锅炉启动时升温速度提高,负荷调节的响应时间缩短,锅炉灰渣含碳量由原来的20％降低到5％以下,机械不完全燃烧损失大为降低.过量空气系数由改造前的2.5 ～3降低至1.2 ～1.3,大幅减少了锅炉排烟量,降低了锅炉排烟热损失.锅炉热效率由改造前的62％提高至改造后的77％ ～ 80％.