亚油酸钠协同二元表面活性剂体系中金红石的浮选特性及机理

利用单矿物浮选试验分别研究了金红石在亚油酸钠与油酸钠或苯甲羟肟酸钠组成的二元表面活性剂体系中的浮选行为,采用Zeta电位、表面张力、接触角、紫外漫反射吸收光谱等手段从气/液、固/液界面探讨了组合药剂之间及组合药剂在金红石表面的作用机制。结果表明,药剂添加顺序对金红石浮选行为有较大影响,亚油酸钠与苯甲羟肟酸钠的协同效应指数要高于亚油酸钠和油酸钠组合体系;组合药剂在金红石表面的吸附可分为单层诱导共吸附和缔合物多层吸附两大类,分子间的缔合作用力及缔合产物的吸附状态是影响组合药剂协同作用及金红石浮选行为的关键因素;苯甲羟肟酸钠和亚油酸钠体系中不同药剂添加顺序下金红石浮选行为与其带隙宽度的变化有较好的一致性,而油酸钠和亚油酸钠体系中则未发现明确的对应关系。     

油酸钠与胲铵类药剂协同浮选金红石的机理

采用单矿物浮选试验研究了金红石在油酸钠和胲铵类药剂组合体系中的浮选行为，利用zeta电位、表面张力、接触角、紫外光谱等手段从界面化学角度详细研究了组合药剂在液液、液固界面的作用机制。结果表明：单一药剂对金红石捕收能力的大小顺序为：油酸钠(SO，51.55%)＞N-亚硝基萘胲铵(CF，18.72%)＞N-亚硝基苯胲铵(NF，14.01%)。组合药剂添加顺序对金红石回收率的影响大小为：先添加N-亚硝基苯胲铵后油酸钠＞先添加油酸钠后N-亚硝基苯胲铵＞油酸钠和N-亚硝基苯胲铵预混后再添加＞油酸钠和N-亚硝基萘胲铵预混后再添 加＞先添加油酸钠后N-亚硝基萘胲铵＞先添加N-亚硝基萘胲铵后油酸钠，该顺序与药剂之间的协同效应指数有较好的一致性。油酸钠分子中的双键与胲铵类分子中的苯环和萘环之间存在电子共轭效应，该效应对组合药剂的吸附特性及缔合行为有较大影响，药剂之间所生成缔合物的数量及空间构象是影响金红石浮选行为的主要原因。     

某低品位金红石精矿的物性测试和可浮性研究

以陕南青山镇金红石矿重选后的低品位金红石精矿为研究对象,通过物性测试研究了其可浮性特征,考察了改性剂浓度、振荡温度、振荡时间、改性剂协同效应等因素对金红石精矿可浮性的影响。结果表明：该金红石精矿属高硅高铁型低品位精矿,主要物相为金红石、榍石、锐钛矿和绿泥石,平均粒度为38.29μm。油酸钠和煤油协同作用体系中,油酸钠浓度0.04 mol·L^-1、煤油用量0.05 mL、振荡温度40℃、振荡时间60 min、p H=7.8条件下,改性后的金红石精矿接触角增大了60.11°,金红石精矿的品位为90.12%,回收率较单纯使用油酸钠提高21.38个百分点;水杨羟肟酸和煤油协同作用体系中,水杨羟肟酸浓度0.08 mol·L^-1、煤油用量0.05 mL、振荡温度40℃、振荡时间90 min、pH=7.8条件下对金红石精矿进行改性,金红石精矿接触角为69.33°,品位为89.51%,回收率较单纯使用水杨羟肟酸提高了22.57%,改性效果良好。本研究结果可为该低品位金红石精矿的综合利用提供基础理论依据。     

长碳链烷基羟肟酸对钛铁矿的浮选性能与机理研究

研究了正癸基羟肟酸和正辛基羟肟酸为代表的长碳链烷基羟肟酸对钛铁矿的捕收性能,考察了矿浆pH、药剂用量对钛铁矿单矿物浮选回收率的影响。结果表明,正癸基羟肟酸对钛铁矿的捕收能力强于正辛基羟肟酸,该两种羟肟酸浮选钛铁矿的最佳pH值在7左右。并采用吸附量测定、红外光谱分析、Zeta电位测定、XPS分析手段研究了正癸基羟肟酸与钛铁矿作用机理。结果表明,正癸基羟肟酸在钛铁矿表面发生了化学吸附和物理吸附。     

长碳链烷基羟肟酸对钛铁矿的浮选性能与机理研究

研究了正癸基羟肟酸和正辛基羟肟酸为代表的长碳链烷基羟肟酸对钛铁矿的捕收性能,考察了矿浆pH、药剂用量对钛铁矿单矿物浮选回收率的影响。结果表明,正癸基羟肟酸对钛铁矿的捕收能力强于正辛基羟肟酸,该两种羟肟酸浮选钛铁矿的最佳pH值在7左右。并采用吸附量测定、红外光谱分析、Zeta电位测定、XPS分析手段研究了正癸基羟肟酸与钛铁矿作用机理。结果表明,正癸基羟肟酸在钛铁矿表面发生了化学吸附和物理吸附。     

胶磷矿与白云石的浮选分离机理研究

白云石与胶磷矿的可浮性相近,二者的浮选分离是磷矿选矿的难点。本文以油酸钠、十二烷基苯磺酸钠、十二烷基硫酸钠及油酸钠与十二烷基苯磺酸钠组合药剂为捕收剂,系统研究了捕收剂种类及浓度、pH值对胶磷矿与白云石浮选分离的影响。结果表明:单捕收剂中油酸钠的捕收效果最好;在十二烷基苯磺酸钠体系中,pH对白云石浮选影响较大,组合药剂比单捕收剂的捕收效果好。     

河南某地金红石矿选矿研究

试验结果表明,选前脱泥对提高原矿品位,改善浮选环境、降低药耗和提高低品位细粒嵌布金红石的选矿回收率至为重要。试验发现,浮选药剂的选用和药剂间的组合搭配,对浮选结果影响也很大。中间试结果表明所选用的浮选工艺是合理的。     

油酸钠体系下Mg2+对白云母的活化机理研究

针对油酸钠体系下Mg2+对白云母浮选行为的影响进行了研究,结合浮选溶液化学、Zeta电位、XPS等手段探讨了Mg2+与白云母的作用机理。结果表明,Mg2+在碱性条件下可以明显提高白云母的可浮性,并且pH值越大Mg2+对白云母的活化效果越好。当pH=12,油酸钠用量为9.20×10-4 mol/L时,3.44×10-4 mol/L的Mg2+可使白云母的回收率提高到82.20%。 Mg2+活化白云母的根本原因在于：Mg2+可强化油酸根离子在白云母表面的局部正电区域的静电吸附作用,同时可以提高白云母表面铝和硅离子与油酸根离子的反应的机率。此外,白云母表面覆盖的Mg2+可与油酸根离子反应生成疏水的油酸镁。在这三者共同作用下,白云母的可浮性得到了显著的提高。     

矿浆pH值对含苯环螯合捕收剂在金红石表面吸附速率的影响

考察了pH和搅拌时间对含苯环螯合捕收剂N-亚硝基苯胲铵和N-亚硝基萘胲铵在金红石表面吸附速率的影响,研究了吸附动力学,进行了量子化学及立体化学分析. 结果表明,N-亚硝基萘胲铵在金红石表面的最大吸附量大于N-亚硝基苯胲铵,但N-亚硝基苯胲铵在金红石表面的吸附速率大于N-亚硝基萘胲铵. 两种药剂的吸附均符合准一级动力学方程,矿物表面活性点离子在矿物表膜中的扩散为吸附的控制步骤. N-亚硝基萘胲铵分子中苯环具有吸电子共轭效应,会影响键合原子的电子云密度和分子结构,从而影响药剂的吸附速率和吸附量.     

羟肟酸对脂肪酸捕收剂流动性的影响

以磷灰石和白云石为研究对象,通过对捕收剂粘度测定、捕收剂表面张力测定、矿物Zeta-电位测定及红外光谱分析,探索羟肟酸对脂肪酸捕收剂流动性的影响,研究脂肪酸+羟肟酸协同用药对白云石、磷灰石浮选的作用机理。研究结果表明,在低温条件下向脂肪酸中加入羟肟酸,可以使脂肪酸溶液粘度大大降低,流动性大为改善;向脂肪酸中加入烷基羟肟酸,能显著降低药剂溶液表面张力,有利于脂肪酸的流动与分散,使药剂与矿物充分作用。     

Flotation separation of ilmenite from titanaugite using mixed collectors

The flotation results show the mixed sodium oleate (NaOL)–benzohydroxamic acid (BHA) collectors at a molar ratio of 4:1 exhibit excellent performance in the flotation separation of ilmenite (FeTiO₃) from titanaugite than NaOL alone at pH 6.0. The mixed collectors NaOL–BHA increase the contact angle, which improves the minerals’ surface hydrophobicity and results in good corresponding flotation recovery. NaOL and BHA are mainly adsorbed chemically on FeTiO₃ and titanaugite, as confirmed by zeta potential tests and Fourier transform infrared (FTIR) analysis. The contact angle results indicated that there is a positive synergistic adsorption of mixed collectors NaOL–BHA on FeTiO₃, thereby enhancing their collecting capacity and selectivity.     

Effects of sodium hydroxide treatment on coordination changes of cobalt ions in CoNaY by means of UV/VIS diffuse reflectance spectroscopy

The coordination changes of Co²⁺ in CoNaY/NaOHs, prepared by cobalt ion-exchange and treatment with NaOH, during dehydration at various temperatures have been investigated by UV/VIS diffuse reflectance spectroscopy. After dehydration of CoNaY/NaOHs at 473 K, the DRS bands show the formation of mixed cobalt oxide species interacted with lattice oxygen. This mixed cobalt oxide species interacted with lattice oxygen decompose during further dehydration at 673 K. The strong intensities of the bands at 660, 575 and 530 nm after dehydration of CoNaY/NaOHs at 873 K indicate that a considerable amount of the cobalt ions remains in the sodalite cage with tetrahedral coordination even after dehydration at 873 K.     

某铜矿选矿实验研究

为了开发某铜矿资源,对其进行了可行性实验研究.根据矿石物相分析结果,采用硫化铜与氧化铜混合浮选工艺,并选用新型高效浮选药剂,可获得铜精品位20.29%,收率70.68%的铜精矿.     

Time dependent wettability of mineral and metal surfaces in the presence of thiol surfactants

The decrease in wettability of mineral and metal surfaces due to the adsorption of surfactants is crucial for flotation recovery and upgrading of these materials in mineral processing. Because of limited residence time in flotation processing, the kinetics of the wettability changes of the mineral surface becomes an important issue. The time dependent wettabilities of silver and galena (PbS) surfaces in aqueous solutions of di-isobutyl dithiophosphinate, a commercial flotation reagent, were determined from in situ measurements of advancing and receding bubble contact angles. Kinetic parameters were calculated from these data. By comparing the in situ measurements with ex situ measurements of water contact angles and external reflection FTIR of the adsorbed organic films on silver, a physical interpretation of the wettability data is given in terms of the evolution of these thin organic films on the mineral surfaces.     

新型氯化钠浮选药剂的研制

采用自行开发的氯化钠浮选剂对旱要光卤石进行选别试验，闭路试验表明，精矿含KCl23.7%,NaCl4．13％，尾矿含KCl2.90%,NaCl84.03%,精矿KCl回收率可达96．79％，NaCl排除率达84．70％。     

复杂多脉型萤石矿的选矿技术进展与展望

萤石作为一种不可再生资源,是重要的非金属矿物,是生产氟工业产品的主要原料,被广泛应用于冶金、化工、建材、轻工、光学、雕刻和国防等领域.随着萤石的应用领域不断拓宽,对萤石的需求量也不断增加,因此,萤石矿的开发和利用愈来愈受到重视.对石英型萤石、方解石型萤石、重晶石型萤石和硫化矿型萤石的选矿方法及采用的药剂制度进行了综述,同时提出采用自动控制精准加药控制药剂的组合与用量,提高药剂的选择性;采用浮选柱精选减少精选次数,简化精选流程;采用选矿与化学处理相结合的方法降低精矿中的杂质含量,提高精矿质量等是提高萤石矿资源回收效率的有效手段,指出了萤石矿选矿今后的研究方向和发展趋势.     

Combination of viscosity regulator and frother to enhance low-rank coal flotation performance

This study investigated the synergistic effect of viscosity regulators (polyethylene glycol, sodium carboxymethyl cellulose, and polyacrylamide) and frother (2-octanol) on upgrading the flotation performance of low-rank coal. The results of flotation tests were consistent with the analysis of induction time and supported by the results of SEM, viscosity, foaming ability, and foam layer stability. In the present work, it was observed that the highest combustible matter recovery was obtained by mixing the polyethylene glycol (PEG300) with 2-octanol, which increased from 32.9% to about 64.4% accompanied by a little increase of ash content (0.54%). Therefore, it demonstrated that the combination of PEG300 and 2-octanol provided the highest combustible matter recovery and better flotation selectivity.     

Influence of temperature on hydroxylation of benzene to phenol using molecular oxygen catalyzed by V/SiO2

Effect of temperature on hydroxylation of benzene to phenol with molecular oxygen as an oxidant was studied over V/SiO₂ using different reductants. The V/SiO₂ with highly dispersed vanadium species was prepared by a sol–gel process and characterized by diffuse reflectance UV–Vis and ESR. This work shows that the onset temperature range of benzene hydroxylation and the temperature reaching the maximum phenol yield differ corresponding to each reductant. The reducing capacity of reductant can be shown by changing temperature and affects, in turn, benzene conversion, product selectivity, and the amount of leaching of V species.