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1.
矿产资源在选矿过程中产生的大量尾矿,既是资源的浪费,又是环境污染源。因此,开展低尾化乃至无尾化综合利用研究,最大程度提高资源利用率是未来矿产资源开发、利用的必由之路。本文在研究国内某复杂多金属矿综合利用时,通过分析所含矿物的基因属性、赋存状态以及嵌布关系,先后进行了钽铌精矿、方解石精矿、锂精矿、云母精矿、长石精矿、石英精矿共计6个产品的选别回收,实现了除少量泥质、铁屑之外的全产品、无尾化综合利用技术路线,可为以后同类型复杂多金属矿的综合回收提供思路借鉴。  相似文献   
2.
《Ceramics International》2022,48(13):18676-18686
A high content of quartz is usually present in Australian gibbsite-boehmite bauxite. The reaction between quartz and sodium aluminate solution at high temperatures in the Bayer process can lead to loss of alumina and sodium oxide. Therefore, to improve alumina recovery, the reaction of quartz needs to be avoided. The digestion behavior of Australian gibbsite-boehmite bauxite and pure quartz in the Bayer process at 230–250 °C was systematically studied in this paper. The mineral composition and morphology of the reaction products were characterized and the kinetics of the quartz dissolution process was studied in detail. It was shown that boehmite in gibbsite-boehmite bauxite can be completely digested at high temperature (250 °C) with a short digestion time (5 min). A short digestion time results in a low reaction rate of quartz in bauxite, and is ideal for alumina recovery at high temperatures. The quartz reaction rate rapidly increases with longer digestion times. The apparent activation energy of the dissolution of quartz in bauxite in the caustic solution is 151.9 kJ mol?1, and the rate-controlling step of this reaction process is the interfacial chemical reaction. By controlling the particle size of bauxite, the digestion temperature, and the digestion time, the reaction rate of quartz in bauxite can be inhibited, which is beneficial for improving alumina recovery and reducing caustic consumption. Therefore, based on the above theoretical research, a process for digesting gibbsite-boehmite bauxite is proposed using high digestion temperature (250 °C), short digestion time (5 min) and large mineral size. An economic benefit of about US$101.9 million for a refinery with the annual output of 2 million tons of alumina can be created by the proposed process.  相似文献   
3.
《Ceramics International》2022,48(6):8004-8011
Integration of advanced and functional materials onto conventional sensing platforms can improve the device performances and even discover new applications. For piezoelectric resonant sensors, an addition of sensing materials can induce damping and hinder a stable device operation. Hence, the development of efficient method for materials integration is important to ensure high-performance and reliable sensor operation. This work presents a direct and precisely controlled integration of graphene oxide (GO) using the electrospray deposition (ESD) onto a 10 MHz Quartz Crystal Microbalance (QCM) for humidity sensing. The proposed ESD method achieves a high mass resolution of a few nanograms. Moreover, the GO uniformly coats across the sensing electrode region as it acts as a ground electrode during ESD. The proposed ESD method also works for a wide range of nanomaterials, such as carbon nanotubes, tin oxide, and silicon carbide micro-and nano-powders. Compared to the conventional drop-casting and dip coating approaches, our method ensures minimal GO agglomeration, resulting in a stable QCM-oscillator operation in a wide range of relative humidity from 11% to 97%. The measurement sensitivity increases with an amount of GO, but less GO results in better noise and detection limit performances. The results shed light on the importance of selecting an optimal amount of sensing materials for stable sensor operations.  相似文献   
4.
箭猪坡矿床是丹池成矿带南端的一个以铅锌锑为主的矿床,随着2012-2014年在箭猪坡矿床钻孔中石英脉型锡矿体的首次发现,打开了箭猪坡矿床新的找矿空间。新发现的锡矿体矿石矿物组合类型主要为锡石+闪锌矿+脆硫锑铅矿+黄铁矿+石英及锡石+脆硫锑铅矿+石英+方解石。箭猪坡矿床锡石呈自形-半自形粒状,锡石粒径多在0.1~0.2mm,少数0.02~0.05mm,分布在含硫化物的石英脉裂隙中。物相分析显示箭猪坡矿床锡主要赋存在锡石中,锡石物相占83.33%~100%。阴极发光(CL)图像显示箭猪坡矿床中的锡石经历了两期结晶作用:早期锡石(Ⅰ)和晚期锡石(Ⅱ),早期锡石CL荧光亮度较小,呈暗灰色至黑色;晚期CL荧光亮度较大,呈白色至浅灰色。锡石单矿物SnO2含量91.623%~96.288%,平均94.03%,杂质主要有Fe、W、In等,其中FeO含量0.02%~0.52%,WO3含量多在0.02~1.34%,In2O3含量在0.476%~0.954%,Sn与FeO、In2O3呈负相关,锡石中FeO、WO3、Ta2O5、Nb2O5、MnO含量指示箭猪坡锡形成于中低-中温热液环境,成矿热液来源于高度分异演化的花岗质岩浆。通过与大厂矿田西矿带上部脉状锡矿体的类比分析,具有相似的成矿条件及矿物组合,推测所揭露到的脉状锡矿(化)体相当于西矿带上部脉状锡矿(化)体,而下部的网脉状、似层状锡矿体尚未揭露到,由此预测箭猪坡矿床深部找矿空间及找矿潜力大。  相似文献   
5.
在油井开采原油时,会产生伴生气,而在高压和低温环境中会生成天然气水合物,进而堵塞运输管道,因此研究油砂体系(含原油的体系)和纯石英砂体系(不含原油的体系)中水合物生成情况具有重要意义。在初始压力为4.00、6.00、8.00 MPa,石英砂粒径为20、30、60、80目,温度恒定的条件下,研究了油砂体系和纯石英砂体系中甲烷水合物的生成情况以及最终耗气量。结果表明,在初始压力相同的油砂体系中,石英砂粒径越小,水合物生成诱导期越短,水合物生成速率越大。研究石英砂粒径对水合物生成最终耗气量的影响发现,随着石英砂粒径的减小,耗气量先增加后减少,当石英砂粒径为60目时,耗气量达到最大,其值为0.19 mol。同时,对油砂体系和纯石英砂体系中水合物生成情况进行了对比。结果表明,由于两种体系中都存在SDS(十二烷基硫酸钠)溶液,因此水合物生成速率相差不大;在石英砂粒径相同的条件下,油砂体系中最终耗气量小于纯石英砂体系中的最终耗气量,这说明原油对水合物生成具有抑制作用。在油砂体系中,压力越大,越有利于水合物的生成。  相似文献   
6.
甘肃某尾矿为选铜尾渣,针对该尾矿性质特点,采用硫浮选—浮选尾矿脱泥—石英反浮选的工艺方案对其进行了综合回收,试验所得硫精矿可销售至硫酸厂,石英精矿可作冶炼造渣原料,试验尾矿可作烧制硅酸盐水泥的原料,实现了该尾矿资源的全综合利用。  相似文献   
7.
针对某金矿,在回收金银的基础上,对金银浮选尾矿进行云母和长石浮选,以及提纯石英试验,最终获得SiO2品位99.91%的石英产品。提纯石英产品与比利时矽比科矿业有限公司石英产品进行对比试验,通过化学成分、粒度组成、熔制、粘度和热膨胀系数测试对比试验,得出金矿提纯石英达到甚至超过矽比科进口石英产品的各项技术指标。  相似文献   
8.
Supercritical water gasification of coal is a clean and efficient method for coal utilization which can convert coal into H2 and CO2. In order to further reduce costs, a novel two-step cascade utilization method was proposed in this study: conducting traditional pyrolysis first and then gasifying the pyrolysis char in supercritical water. The influences of different pyrolysis operating parameters on gaseous products and char gasification in supercritical water were investigated. Quartz tube reactors were used to ensure the complete collection of gaseous products in pyrolysis process. The experimental results showed that both carbon and hydrogen conversion efficiency increased with temperature, and the increasing trend became not obvious after reaction for 5 min. The thermo-gravimetric curves showed that volatilization removal process was completed at the pyrolysis time of 5 min and higher pyrolysis temperatures were beneficial to the subsequent gasification process. The result also showed that residual weight was 15%–20% of the initial weight. Hydroxyl radicals kept stable during pyrolysis process with the absorption peak intensity increasing first and then decreasing, and mineral substance disintegrated gradually as time increased. As pyrolysis temperature increased, the peak of CC double bonds decreased, turning into stable functional groups and carbonyl group increased. Dispersive pores occurred at the surface of coal as residence time increased with particle size decreasing, specific surface area and reactivity increasing. The results might be used for the design of a cascade utilization system based on coal gasification in supercritical water.  相似文献   
9.
A new type collector α-Bromodecanoic acid (CH3(CH2)7CHBrCOOH, α-BDA) was synthesized by solvent-free method (Hell–Volhard–Zelinski reaction) in laboratory for the flotation of quartz mineral at a relatively low temperature of 16 °C. The adsorption mechanism of α-BDA collector on quartz mineral surface was established by zeta potential measurements, contact angle measurements, Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS), in conjunction with the results of quartz micro-flotation tests. The flotation results showed that the activator Ca(II) functioned as an indispensable and crucial factor on the recovery of pure quartz. When the quartz was floated with α-BDA alone at strong alkaline conditions (pH  11.50), the recovery rate reached to only 11.9%. However, when using the activator Ca(II) at a concentration of 4 × 10−4 mol/L, the collector exhibited an excellent performance, where about 99.5% of the quartz had been floated at or above pH value 11.50 at 16 °C. The study revealed that the α-BDA collector had adsorbed on the surface of pure quartz in the forms of electrostatic interaction, hydrogen bonding and chemical adsorption based on the results of zeta potential measurements, contact angle measurements, FT-IR spectra, and XPS.  相似文献   
10.
针对铁矿石反浮选过程中药剂使用时所需矿浆温度高,开发了适合捕收细粒级石英的阳离子捕收剂。通过一系列浮选试验及接触角、Zeta电位和红外光谱检测考察了此阳离子捕收剂对石英的捕收性能和两者的作用机理。结果表明,温度为18℃和p H=9.45时,阳离子捕收剂DBA-2对38μm粒级石英有很高的浮选回收率;在此条件下,对74~38μm粒级石英浮选效果不佳,阳离子捕收剂DBA-2更适用于微细粒铁矿反浮选中应用。接触角测量结果说明,添加DBA-2使石英表面接触角增大,可浮性增强,在20~30°之间,接触角发生的微小变化会对回收率产生巨大影响。Zeta电位测试结果表明,在纯水中石英的零电点为p H=2.26,与DBA-2作用后,零电点偏移至9.47,说明DBA-2在石英表面有吸附作用的发生。通过红外光谱检测分析,DBA-2在石英表面的吸附主要是静电吸附和氢键吸附。  相似文献   
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