Ca(ClO)2与腐殖酸钠对黄铜矿和黄铁矿浮选的影响

纯矿物试验和人工混合矿试验表明,Ca（ClO）2与腐殖酸钠都对黄铁矿具有很好的抑制作用,而不抑制黄铜矿,二者组合使用能更加有效抑制黄铁矿.根据杨氏方程结合接触角的测定结果,计算矿物表面润湿能,结果说明腐殖酸钠和Ca（ClO）2组合抑制剂对黄铁矿的良好的抑制性能,是二者协同作用的结果.     

磷矿擦洗尾矿浮选试验研究

针对云南某地硅钙质擦洗尾矿，采用SJ-01为调整剂，分别在粗选用水玻璃，一次精选用FS作抑制剂，油酸钠和煤油乳化后的复合药剂为捕收剂的浮选工艺流程，获得了精矿P2O5 31．05％、回收率86．08％的浮选指标。     

Effect of Flow Improvers on the Rheological Properties of Gas Oil and Their Raffinates

Abstract

The gas oil feedstock was solvent extracted with pyrrolidone (NMP) at different temperatures (50°C–70°C) and at different solvent feed ratios (ranging from 2/1 to 5/1.) The raffinates were treated with four flow improvers additives; two synthesized improvers (poly NAFOL 1822C palmitate-Co-N,N ditallowamine phthalic diamide and poly NAFOL 1822C palmitate Co-N,N ethanolamine phthalic diamide) and two available commercial improvers 2437 (Com.1) & commercial wax dispersant CWD-11 (Com.2) to study their efficiencies and suitabilities for improving the rheological properties. The efficiency of the additives in reducing the pour point of gas oil and their raffinates is in the order: Sec > Et > Com1 > Com2.     

The effect of the reagent suite on froth stability in laboratory scale batch flotation tests

In batch flotation tests conducted on ores from the Merensky reef, changes in froth stability invariably occur with variations in the reagent suite. The main reagents are collectors (primary and secondary), activators, depressants and frothers. Since the particles entering and leaving the froth in a batch flotation system are continuously changing, the stability of the froth can vary. Under these conditions the simplest measure of froth stability is the measure of water recovery at a fixed froth height. The batch flotation system developed at UCT allows for the separation of gangue which is entrained relative to gangue which is floated. It has been found that the presence of naturally floatable gangue (NFG) leads to froth stabilisation, whereas the presence of hydrophobic sulfide minerals may lead to destabilisation of the froth depending on the hydrophobicity (contact angle) of the sulfide minerals. This can vary with ore type since particle shape and amount of particles present can influence the extent of destabilisation. At low depressant dosages sodium isobutyl xanthate (SIBX) always results in lower froth stability than sodium ethyl xanthate (SEX). The frothing nature of dithiophosphate leads to increased froth stability and the addition of copper sulfate results in destabilised froths. Increasing depressant dosage reduces the stabilising influence of NFG and the depressant type (guar gum or CMC) also affects froth stability. Frother can be used in an attempt to overcome the destabilising effects of high depressant dosage. This work examines the effect of variations in the reagent suite and uses water recovered at a fixed froth height as an indication of froth stability in order to analyse these effects on the recovery of sulfide minerals, floatable gangue and entrained gangue.     

The effect of acrylamide-co-vinylpyrrolidinone copolymer on the depression of talc in mixed nickel mineral flotation

Copolymers of acrylamide and vinylpyrrolidinone with varying compositions have been synthesised and employed to depress talc in a model flotation system with process plant operation conditions. Adsorption isotherms indicated that the hydrophilic acrylamide homopolymer has a very low affinity for the hydrophobic talc surface, whereas vinylpyrrolidinone homopolymer strongly adsorbs onto the talc surface. Micro-flotation experiments revealed that the copolymer system can induce stronger talc depression than the homopolymer variants, with the most effective copolymer depressant having 25-30% vinylpyrrolidinone incorporation. The copolymer system is observed to have inherited the strong talc affinity of vinylpyrrolidinone polymer and the strong hydrophilic property from polyacrylamide. This combined effect facilitates the desired strong talc depression in single mineral flotation. However, this copolymer system has similar adsorption affinity on both the talc and pentlandite, hence depressing both talc and pentlandite in the mixed mineral flotation system. This research shows that a sufficient hydrophobic balance on the polymer is necessary for the adsorption and subsequent depression for talc. However, polymer with high adsorption selectivity is required to be a successful synthetic talc depressant for mixed mineral system.     

Effect of MC–MA polymer pour point depressants on the flow properties of biodiesel

To generate efficient pour point depressants (PPDs) for biodiesel, this study prepared a series of MC–MA polymers and their cold flow properties on biodiesel were studied by determining their solid points (SPs) and cold filter plugging points (CFPPs). This study also investigated the performance mechanisms of these polymers through differential scanning calorimetry (DSC) and rheological mechanics to identify the low-temperature crystal morphology and crystallization behavior of the biodiesel samples. Results indicated that compared with other polymers, the synthesis of polymer PPD2 could satisfactorily improve the low-temperature flow properties of biodiesel without altering other important fuel properties.     

铜镍硫化矿浮选过程中MgO脉石矿物的抑制途径探析

我国镍矿石资源主要为富含MgO硅酸盐脉石矿物的低品位铜镍硫化矿。长期以来,以金川公司为代表的主要铜镍矿山,一直将浮选精矿降镁作为选矿技术攻关的重点。尽管国内外研究人员开展了大量的研究工作,铜镍硫化矿浮选过程中MgO脉石矿物的抑制至今未能在技术上找到可控的解决方法。文章对MgO脉石矿物抑制研究的相关文献进行了综述分析,提出采用复合抑制剂,即络合剂-抑制剂组合,先对有用矿物和脉石矿物进行表面清洗以扩大其可浮性差异,再选择性抑制MgO脉石矿物,这将是铜镍硫化矿浮选过程中抑制MgO硅酸盐脉石矿物的有效途径。     

镍黄铁矿浮选中抑制剂的作用

介绍了蛇纹石对镍黄铁矿浮选的影响,解释了几种常用抑制剂的作用机理。六偏磷酸钠和水玻璃主要通过生成亲水性的配合物,改变蛇纹石的表面电性而起分散和抑制作用;羧甲基纤维素主要通过氢键有与蛇纹石表面的金属离子发生化学吸附而起絮凝和抑制作用;提出了在镍黄铁矿浮选中选用抑制剂的研究思路。     

四川某难选硫化铅锌银矿石浮选试验

针对四川某铅锌银矿原选矿工艺不能适应矿石性质变化,而且在流程中使用氰化物的问题,对该矿矿石重新进行了浮选试验,结果表明：在-0.074 mm占85%的磨矿细度下,以石灰为调整剂、硫酸锌+亚硫酸钠为抑制剂、乙硫氮为捕收剂优先选铅,选铅尾矿以硫酸铜为活化剂、丁黄药为捕收剂选锌,可获得铅品位为51.80%、铅回收率为64.75%的铅精矿和锌品位为53.55%、锌回收率为91.83%的锌精矿,银在铅、锌精矿中的总回收率达到83.75%。试验不仅使铅、锌、银的回收率与现场工艺相比有明显提高,而且实现了铅锌无氰分离。     

钛铁矿浮选中的抑制剂研究

钛铁矿的浮选近年来受到极大关注,但对浮选药剂的研究多集中在捕收剂上,对抑制剂的研究相对较少。常用抑制剂有水玻璃、羧甲基纤维素和草酸等。本研究对比了多种抑制剂在钛铁矿浮选中对脉石的抑制效果以及对钛铁矿的分选性,并进行了系统的单矿物试验,最终证明对钛铁矿浮选而言,羧甲基纤维素是现有抑制剂中最为有效的,同时对羧甲基纤维素的抑制机理进行了探讨,认为竞争吸附很有可能是羧甲基纤维素在钛铁矿浮选中对脉石具有良好抑制效果的原因。