CMC和古尔胶对滑石浮选的抑制作用研究

通过浮选试验、接触角测量、动电位测定和红外光谱研究了弱碱性条件下羧甲基纤维素钠(CMC)和古尔胶对滑石浮选的抑制性能及作用机理。结果表明,弱碱性条件下CMC和古尔胶是滑石浮选的有效抑制剂,低用量古尔胶能较好地抑制滑石,古尔胶的抑制作用强于CMC;在CMC和古尔胶作用下,滑石一级浮选速率常数减小,浮选速率降低,回收率下降。CMC和古尔胶吸附在滑石表面,使滑石表面润湿性增强、可浮性变差;CMC使滑石表面负电性增强,古尔胶使滑石表面负电性减弱。阴离子CMC主要通过—COO-和—OH吸附在滑石表面,中性古尔胶主要通过—OH吸附在滑石表面。     

不同矿浆温度下滑石表面甲基纤维素脱附行为研究

通过浮选试验及脱附试验,研究不同矿浆温度下滑石表面上甲基纤维素脱附行为及其对滑石浮选的影响。结果表明,滑石天然可浮性较好,甲基纤维素对滑石具有一定的抑制作用,其抑制效果随矿浆温度升高而增强,水洗能够减弱甲基纤维素对滑石的抑制作用,使滑石浮选回收率升高,且低温水洗时滑石的浮选回收率增加更多。使用甲基纤维素能够实现黄铜矿和滑石的浮选分离。      

滑石的矿物结构与浮选性能

滑石矿是在国民经济中占有重要地位的矿种之一,为给我国滑石资源的高效利用提供参考,系统研究了滑石的结构及其浮选性能。滑石为层状结构硅酸盐矿物,层间解离极完全,滑石晶体破碎解离后,有2个性质不同的面,基面疏水性较好,端面疏水性略差,滑石矿物具有非常好的天然疏水性。水介质中,碱金属离子Na^+、K^+会破坏滑石表面的水化膜,提高滑石的天然可浮性;多价金属离子存在时,会以金属离子、羟合络离子或氢氧化物沉淀的形式吸附在滑石表面,只有当氢氧化物吸附在滑石表面时,滑石受抑制,pH升高后,吸附在滑石表面的氢氧化物会脱落,滑石的天然可浮性恢复。煤油与起泡剂混合使用可以提高滑石的回收率,但由于煤油分散性差,浮选过程不太稳定,特别是煤油与松油醇共用时;胺类捕收剂在低pH条件下对滑石的浮选效果较好,高碱性下,胺类捕收剂在矿浆中的分散性变差,作用效果也会与煤油相似,严重影响浮选泡沫性能,恶化浮选效果;油酸不太适宜用于滑石的浮选,使用油酸时可考虑用多价金属离子做滑石的活化剂;阴离子型高分子抑制剂分子中的疏水基团会与疏水性的滑石基面通过范德华力产生物理吸附,而亲水性基团朝外,从而使滑石表面亲水而被抑制;多糖类抑制剂只能通过物理吸附在滑石表面;聚丙烯酰胺经N原子改性后,对滑石抑制效果显著。     

多糖抑制剂的化学成份和分子量对滑石浮选的影响

选矿工业中经常使用多糖抑制剂报制具有天然可浮性的脉石来提高精矿品位。微浮选研究结果表明，在10^-3mol/L KNO3离子浓度下，多糖抑制剂的用量、分子量和化学组成等会影响多糖抑制剂对滑石的抑制作用。对4种羧甲基纤维素（CMC）和3种改性的古尔胶药剂的黏度数据进行了测试，并对各种CMC的分子量进行了估算。当体系中加入了含古尔胶的聚合物之后，滑石的天然可浮性不仅会降低，而且滑石受到的抑制作用也会随着古尔胶分子量的增大而增强。较低用量的古尔胶可强烈抑制滑石，进一步增大古尔胶用量不会再增强它对滑石的抑制作用。在10^-5mol/L KNO3条件下，CMC不是滑石的有效的抑制剂。CMC分子量的改变对滑石抑制体系没有产生任何变化，但增大CMC的浓度会使抑制作用稍稍得到增强。本文根据以上这些研究和有关的文献提出了聚合物与滑石相互作用的机理。     

羧甲基纤维素的应激反应规律及对滑石表面疏水性的影响

通过浮选实验、接触角测试、动电位测量及红外光谱试验研究不同的溶液条件对吸附在滑石表面的羧甲基纤维素(CMC)作用效果的影响,并考察其作用机理。结果表明,滑石具有较好的天然可浮性,CMC能够吸附在滑石表面,降低滑石的表面疏水性。吸附后的CMC对滑石的抑制作用效果受溶液pH及溶液中离子的浓度影响较大。当吸附有CMC的滑石位于pH=9的溶液中,CMC的羧甲基之间存在较强的静电排斥作用,吸附的CMC分子呈伸展状态存在,形成的吸附层较薄,造成的亲水性较弱;当矿浆pH变为酸性或溶液中有离子存在时,CMC羧甲基之间的静电排斥作用减弱,CMC分子在滑石表面呈蜷缩状态,所形成的吸附层较厚,造成的亲水性较强,这种变化是可逆的。     

甲基纤维素作为抑制剂浮选分离黄铜矿和滑石

通过浮选试验、Zeta电位测试、TOC测试及红外光谱测试对甲基纤维素在黄铜矿与滑石浮选分离中的作用及其在两种矿物表面的吸附机理进行了研究。浮选试验结果表明,低用量的甲基纤维素可有效抑制滑石,但对黄铜矿抑制效果很弱,可实现黄铜矿与滑石的浮选分离。甲基纤维素作为滑石的抑制剂,浮选分离黄铜矿和滑石混合矿。人工混合矿Cu品位为15.19%时,可以获得铜精矿Cu品位为24.08%,回收率达74.68%的指标。检测结果表明,甲基纤维素在黄铜矿和滑石表面均发生了物理吸附,且在滑石表面的吸附强于在黄铜矿表面的吸附。     

硫化矿浮选中滑石抑制剂的研究进展

许多硫化矿常与滑石等镁硅酸盐矿物共存，滑石因其良好的可浮性影响硫化矿浮选分离，影响硫化矿选矿综合指标，对于这类硫化矿常通过抑制滑石实现二者的浮选分离，故对滑石抑制剂及其作用机理进行研究有着重要的意义。本文综述了滑石抑制剂研究进展，滑石抑制剂分为无机类和有机类，无机抑制剂如水玻璃、六偏磷酸钠等在硫化矿浮选中被广泛应用，其抑制机理主要为水解后形成的物质吸附于滑石表面，从而使得滑石亲水；高分子有机抑制剂如CMC、古尔胶等对滑石抑制能力较强，选择性较好，此类药剂主要是通过羟基、羧基与滑石形成氢键、化学键，使滑石亲水，实现硫化矿与滑石的浮选分离。采用有效的高分子抑制剂是今后实现滑石与硫化矿浮选分离的主要方向，而高分子抑制剂中-OH与-COOH是抑制滑石的主要官能团，这为滑石抑制剂的改性、设计与开发提供了依据。      

铜离子对CMC浮选分离滑石和黄铁矿的影响

为实现黄铁矿和滑石更好地浮选分离，基于CMC对滑石抑制能力不强的弱点，在pH值为9的条件下，以CMC作为抑制剂，戊黄药作为捕收剂，探究了铜离子的加入对滑石和黄铁矿浮选的影响。结果表明，浮选过程中加入铜离子，在不影响黄铁矿浮选的情况下（浮选回收率90.8%），有效的抑制了滑石的浮选（浮选回收率由57.07%降低到8.99%）。另外还对CMC和铜离子加药顺序做了探究，发现铜离子在CMC前加入不影响黄铁矿的浮选，但更有利于滑石的抑制。     

胶类抑制剂对滑石的抑制行为及机理

为寻找硫化矿物与滑石的选择性抑制剂,通过浮选试验、吸附量测试、zeta电位测试和红外分析,研究4种胶类抑制剂的抑制行为差异,分析了抑制作用机理,考察4种胶类抑制剂对混合矿分离的影响。单矿物浮选试验结果表明,滑石天然可浮性较好,4种胶类抑制剂均能有效抑制滑石的上浮,抑制作用由强到弱为刺槐豆胶、瓜尔豆胶、黄原胶、果胶。吸附量试验结果表明,4种胶类抑制剂均在滑石表面发生吸附。zeta电位测试和红外光谱分析表明,胶类抑制剂的吸附是一种以疏水作用为主的物理吸附作用。混合矿浮选试验结果表明,刺槐豆胶能有效分离黄铜矿和滑石混合矿;果胶、黄原胶、瓜尔豆胶对黄铜矿也有一定的抑制效果,导致铜精矿回收率较低。因此,刺槐豆胶可以作为瓜尔豆胶的代替抑制剂。     

金属离子对滑石浮选行为的影响及机理研究

滑石常存在于硫化矿中影响硫化矿浮选精矿的质量。为了解金属离子对滑石浮选行为的影响和作用机制,考察了Ca²⁺、Mg²⁺、Cu²⁺、Fe³⁺对滑石纯矿物浮选、滑石表面ζ电位及滑石与气泡之间诱导时间的影响。结果表明：Ca²⁺、Mg²⁺、Cu²⁺、Fe³⁺均可在滑石表面形成吸附;Ca²⁺对滑石可浮性影响不大;添加Mg²⁺后,当pH＞10时,滑石可浮性降低;添加Cu²⁺后,滑石在pH=4~10范围被抑制,并且在pH值为6左右时Cu²⁺对滑石抑制作用最强;Fe³⁺在pH=3~9的范围内能够抑制滑石,并且在pH值为7左右时对滑石抑制作用最强。溶液化学计算结果表明,溶液中的金属络合离子可以改变滑石的表面电位,而氢氧化物沉淀吸附在滑石表面会降低滑石的可浮性。静电作用能计算结果表明：当pH值低于氢氧化物的零电点时,金属离子形成的氢氧化物沉淀会特定地吸附于滑石表面,产生多相凝聚,导致滑石表面亲水性增强,可浮性降低;当pH值大于氢氧化物的零电点时,凝聚现象减弱,滑石表面疏水性增强,可浮性提高。试验结果对含滑石硫化矿中滑石的抑制和分离有一定的指导作用。     

The use of ToF-SIMS and microflotation to assess the reversibility of binding of CMC onto talc

Carboxymethyl cellulose (CMC) is commonly used as a depressant for talcaceous minerals. To assess whether CMC depressants are strongly, or weakly and reversibly bound to the surface of talc, desorption experiments were conducted on New York talc. The floatability was monitored through microflotation experiments, combined with the determination of the CMC coverage on talc by ToF-SIMS. CMC adsorption and desorption were carried out in distilled water and in electrolyte containing Ca²⁺ ions. CMC adsorption levels were higher using Ca²⁺ electrolyte, in line with the depression behavior in the microflotation tests. Washing did not affect the flotation behavior. ToF-SIMS showed that CMC coverage of the talc particles was good and the distribution homogeneous. Adsorption and subsequent desorption in distilled water however, showed a partially restored floatability after desorption, which could be related to an inhomogeneous CMC distribution on the talc surface as shown by ToF-SIMS. By additional exposure to Ca²⁺ ions CMC redistribution occurs causing depression.     

The effect of a new polysaccharide on the depression of talc and the flotation of a nickel–copper sulfide ore

The effect of the depressant galactomannan (KGM) on the depression of talc and the flotation of a nickel–copper sulfide ore have been investigated through microflotation, batch flotation and industrial flotation tests, zeta potential and infrared spectrum measurements. The flotation results indicated that KGM had a straining influence on the depression of talc while had little effect on nickel minerals flotation. Compared with the depressant carboxymethyl cellulose (CMC) and guar gum, the KGM increased the nickel recovery dramatically, it not only negated the need for a talc removal process, but also achieved a significant decrease in the depressant consumption by half. Zeta-potential and infrared spectrum measurements illustrated that chemical adsorption was seen between KGM and talc, and a possible weak physical adsorption was seen between KGM and pentlandite. This was the reason why KGM had high depression selectivity for talc and little depression effect on nickel minerals.     

抑制剂对滑石和透闪石可浮性影响试验研究

在滑石矿中,脉石矿物透闪石会对滑石的浮选效果产生影响。进行了滑石和透闪石纯矿物浮选试验,研究十二烷基苯磺酸钠体系中不同抑制剂对滑石矿物可浮性的影响。结果表明:以十二烷基苯磺酸钠为捕收剂,在碱性条件下,六偏磷酸钠和植酸抑制透闪石的浮选,但对滑石浮选抑制作用不明显;而羧甲基纤维素钠对滑石和透闪石的浮选有很强的抑制作用。当十二烷基苯磺酸钠用量为160 mg/L,植酸用量为60 mg/L,p H值为8.6时,滑石和透闪石的回收率分别为80%和12%,可有效实现两种纯矿物的分离。     

Adsorption of tailored carboxymethyl cellulose polymers on talc and chalcopyrite: Correlation between coverage,wettability, and flotation

A carefully chosen selection of CMC polymers was used to probe the depression of talc and chalcopyrite and to highlight the effect of specific alterations of the bulk polymer chemistry on the power and selectivity of the depressants. In situ tapping mode atomic force microscopy (AFM), captive bubble contact angle measurements, and flotation tests were used to study the adsorption of the CMC polymers on chalcopyrite and talc. The degree of substitution and distribution of substitution of carboxymethyl groups on CMC was seen to have a strong influence on the ability of the polymers to adsorb onto the surface of talc and chalcopyrite. High substitution results in low coverage on both minerals whereas low substitution results in higher coverage. The influence of distribution of substitution (random or clustered) was also seen to affect the adsorption, with more random/even substitution giving rise to greater adsorption on talc and chalcopyrite. The contact angle of talc and chalcopyrite is significantly altered in the presence of the three polymers, with increased surface coverage (determined by AFM) correlating with the ability of the polymers to decrease the wettability of talc and chalcopyrite. This trend was also followed in single and mixed mineral talc and chalcopyrite flotation.     

Fundamental study on talc–ink adhesion for talc-assisted flotation deinking of wastepaper

Effective removal of ink particles by froth flotation is of up-most importance in paper recycling. In this study, the potential use of talc particles as carriers of difficult-to-float fine ink particles is investigated. In order to facilitate ink particle removal by carrier flotation, the interactions between talc and oily-ink particles in aqueous solutions containing flotation chemicals are studied by zeta potential distribution measurements and with the impinging jet apparatus. The chemical conditions under which talc–ink aggregation occurs are identified and reported.     

金川矿石中脉石矿物易浮原因的探讨

通过对金川原矿矿石性质研究和精矿及尾矿中硫化矿物的XPS表面测试、扫描电镜统计及能谱测试,探索了金川矿石中脉石矿物易浮的原因。结果表明,金川硫化物表面易与镁结合,蛇纹石表面常有墨铜矿及羟镁硫铁矿,这两个矿物在蛇纹石表面形成使蛇纹石向滑石转变,蛇纹石表面已滑石化或为蛇纹石与滑石的过渡相,这是造成金川脉石矿物易浮且难以抑制的原因。