【摘要】：鎳黃鐵礦常與黃銅礦賦存,兩者可浮性相近且表面都易氧化造成可浮性下降難以分選富集,而常規(guī)高堿抑鎳浮選效果較差,在銅鎳分離過(guò)程中部分鎳礦物進(jìn)入銅精礦中,造成鎳精礦中鎳銅比下降,鎳回收率降低,因此對(duì)鎳黃鐵礦和黃銅礦的表面氧化過(guò)程和機(jī)制進(jìn)行相關(guān)研究,對(duì)提高銅鎳資源的利用率意義重大。本文考察了鎳黃鐵礦和黃銅礦在不同p H介質(zhì)和捕收劑濃度條件下的表面氧化電化學(xué)作用機(jī)理,獲得以下主要結(jié)論:(1)由鎳黃鐵礦和黃銅礦表面氧化的Eh-p H分析,推測(cè)出了硫化礦物表面氧化的發(fā)生趨勢(shì),結(jié)合無(wú)捕收劑體系下的循環(huán)伏安曲線研究可知,兩種硫化礦表面氧化的程度決定了其表面性質(zhì)和可浮性。適度氧化的氧化產(chǎn)物為疏水性的單質(zhì)硫,硫化礦表現(xiàn)出良好的無(wú)捕收劑可浮性;深度氧化產(chǎn)物則為金屬氫氧化物和金屬硫酸鹽等親水性物質(zhì),硫化礦表面親水。硫化礦表面易在高堿和高電位條件下發(fā)生深度氧化。(2)兩種硫化礦無(wú)捕收劑體系下的Tafel曲線研究表明,p H值對(duì)兩種硫化礦在體系中的腐蝕動(dòng)力學(xué)參數(shù)均有影響,在相同p H值體系中,黃銅礦的腐蝕電位corrE更負(fù)移、腐蝕電流密度corri更大,說(shuō)明黃銅礦更易發(fā)生腐蝕。(3)鎳黃鐵礦和黃銅礦在黃藥捕收劑體系中的靜電位和電化學(xué)測(cè)試表明,硫化礦在丁黃捕收劑中陽(yáng)極反應(yīng)為疏水性雙黃藥的氧化生成,且其氧化速率遠(yuǎn)遠(yuǎn)大于硫化礦自身的氧化速率,說(shuō)明捕收劑的加入,大大增強(qiáng)了硫化礦物表面的氧化進(jìn)程。浮選體系p H超過(guò)硫化礦浮選臨界p H時(shí),硫化礦強(qiáng)烈的自身氧化將占主導(dǎo)地位,此時(shí)礦物表面將覆蓋金屬氫氧化物、金屬硫酸鹽等親水性氧化產(chǎn)物,阻滯捕收劑雙黃藥在礦物表面的形成,降低其表面疏水性。反之,在浮選臨界p H以內(nèi),礦物表面雙黃藥的生成反應(yīng)將占主導(dǎo)地位,生成的雙黃藥在礦物表面形成吸附,使礦物表面疏水。(4)硫化礦物的電化學(xué)動(dòng)力學(xué)研究表明,捕收劑在礦物表面陽(yáng)極氧化生成的疏水性雙黃藥分子層厚度差異使硫化礦物表面的親疏水程度不同,進(jìn)而影響硫化礦的可浮性。
[Abstract]:Nickel pyrite often occurs with chalcopyrite, both of which are similar in floatability and easy to be oxidized on the surface. It is difficult to separate and enrich floatability due to the decrease of floatability, but the effect of conventional high-alkali nickel suppression flotation is poor. During the separation of copper and nickel, some nickel minerals enter the copper concentrate. The ratio of nickel to copper in nickel concentrate decreases and the recovery rate of nickel decreases. Therefore, it is of great significance to study the surface oxidation process and mechanism of nickel pyrite and chalcopyrite in order to improve the utilization ratio of copper and nickel resources. In this paper, the electrochemical mechanism of surface oxidation of nickel pyrite and chalcopyrite in different pH medium and collector concentration is investigated. The main conclusions are as follows: (1) Eh-p H analysis of surface oxidation of nickel pyrite and chalcopyrite; The occurrence trend of surface oxidation of sulphide minerals was inferred and the surface properties and floatability of the two sulphide minerals were determined by the degree of oxidation in combination with the cyclic voltammetry curves in the system without collector. The oxidation product of moderate oxidation is hydrophobic simple sulfur, the sulphide ore shows good floatability without collector, and the deep oxidation product is hydrophilic substance such as metal hydroxide and metal sulfate, and the surface of sulphide ore is hydrophilic. The surface of sulphide ore is easily oxidized deeply under high alkali and high potential conditions. (2) the Tafel curves of the two kinds of sulphide ores without collector system show that the, p H value has influence on the corrosion kinetic parameters of the two sulphide ores in the system. In the same pH system, the corrosion potential (corrE) of chalcopyrite is more negative, and the corrosion current density (corri) is larger. (3) Electrostatic potential and electrochemical measurements of nickel pyrite and chalcopyrite in xanthate collector system showed that the anodic reaction of sulphide ore in butadiene collector resulted in hydrophobic double xanthate oxidation. The oxidation rate of sulphide minerals is much higher than that of sulphide minerals, which indicates that the addition of collector greatly enhances the oxidation process of sulphide minerals. When the flotation system pH exceeds the critical pH of sulphide flotation, the strong autooxidation of sulphide will dominate, and the surface of the mineral will be covered with hydrophilic oxidation products such as metal hydroxide, metal sulfate, etc. The formation of the collector dixanthate on the mineral surface was retarded and its hydrophobicity was reduced. On the contrary, within the flotation critical pH, the formation reaction of dixanthate on mineral surface will dominate, and the formed dixanthate adsorbs on the mineral surface, which makes the mineral surface hydrophobic. (4) the electrochemical kinetic study of sulphide minerals shows that, The hydrophobic dixanthate formed by anodic oxidation of the collector on the mineral surface has different hydrophobic degree, which affects the floatability of sulphide ore due to the difference of the molecular layer thickness of the hydrophobic double xanthate on the surface of the sulphide mineral.
【學(xué)位授予單位】：江西理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TD923

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 R.A.Hayes;李海紅;;控制E_h電位的硫化礦無(wú)捕收劑浮選分離[J];國(guó)外金屬礦選礦;1991年12期

2 G·布魯特 ,白秀梅,肖力子;雙黃藥在黃鐵礦浮選中的作用:可溶性、吸附研究、Eh和FTIR測(cè)定[J];國(guó)外金屬礦選礦;2002年12期

3 覃文慶，，王淀佐，李柏淡，邱冠周;硫化銅礦硫誘導(dǎo)浮選研究與應(yīng)用[J];湖南有色金屬;1995年06期

4 覃文慶,邱冠周,徐競(jìng),王淀佐;黃原酸鹽介質(zhì)中黃鐵礦的電化學(xué)行為(1)雙黃藥在其表面形成的電極過(guò)程[J];有色金屬;1999年03期

相關(guān)博士學(xué)位論文 前1條

1 孫偉;高堿石灰介質(zhì)中電位調(diào)控浮選技術(shù)原理與應(yīng)用[D];中南大學(xué);2001年

本文編號(hào)：2327784