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Beneficiation of gold sulphide ores from South Sardinia, Italy
Published in Gülhan Özbayoğlu, Çetin Hoşten, M. Ümit Atalay, Cahit Hiçyılmaz, A. İhsan Arol, Mineral Processing on the Verge of the 21st Century, 2017
M. Ghiani, A. Serci, R. Peretti, A. Zucca
Xanthates, commonly used for sulphides and native metals flotation were used as collectors. Preliminary tests were conducted to define: – type of xanthate, whose flotation effectiveness varies with length of the hydrocarbon chain;– depressants capable of ensuring the required selectivity;– optimum quantities;– type of flotation medium (industrial water, waste water from the cyanidation process with free CN concentrations of 40 mg/1 and pH of 8.7, or a mixture of the two;– the process flowsheet for industrial scale up.
Froth flotation
Published in D.V. Subba Rao, Mineral Beneficiation, 2011
Xanthates, Dithiophosphates (known as Aerofloats), Dithiocarbamates, Fatty acids and soaps are the important anionic collectors. Xanthates are the most widely used collectors for flotation of sulphide minerals. The general formula of sodium or potasium xanthate is:
Resources and Processing
Published in C. K. Gupta, Extractive Metallurgy of Molybdenum, 2017
Classification of collectors, as pointed out in an earlier paragraph, is presented in Figure 14. The most widely used among the anionic collectors are the xanthates and the aerofloat collectors. Xanthates are the most important and the oldest reagent group used as collectors in the flotation of sulfide minerals. Their preparative process has been pointed out in the figure. They are readily soluble in water and used in alkaline pH circuits because of their instability in acid pH environments. The most widely used xanthates are ethyl, isopropyl, isobutyl, amyl, and hexyl. To take names of some specific compounds among the various xanthates, mention may be made of potassium amyl xanthate (trade name Z-6, developed by Dow Chemical; R.350, developed by American Cyanamid) and sodium isopropyl xanthate (Z-11, developed by Dow Chemical; R.343, developed by American Cyanamid). These are the most popular ones and are followed in importance by dithiophosphates, especially by sodium disec butyl (trade name R.238, developed by American Cyanamid). Combination of collectors when used may include, as for instance, xanthates with xanthic esters-allyl amyl xanthic ester (trade name R.3302, developed by American Cyanamid; 1750 developed by Minerec); allyl hexyl xanthic ester (trade name R.3461, developed by American Cyanamid; 2023, developed by Minerec). Isopropyl ethyl thionocarbonate (trade name Z-200, developed by Dow Chemical; 1661, developed by Minerec) is another frequently used commercially available collector. The list of collectors also includes kerosene, vapor oil, fuel oil, transformer oil, and other hydrocarbons. The structures of two anionic collectors, sodium ethyl xanthate (trade name Z-4, developed by Dow Chemical; R.303, developed by American Cyanamid) and sodium dithiophosphate (R.3418, developed by American Cyanamid), and their attachment features with a mineral particle are shown in Figure 15. In the case of Z-4, the anion consists of a hydrocarbon nonpolar radical and a connected polar group. The cation (sodium) plays no part in the reagent-mineral reaction. The dithiophosphates have pentavalent phosphorus in the polar group, rather than tetravalent carbon.
Modification and regulation of acid-activated kaolinite with TiO2 nanoparticles and their enhanced photocatalytic activity to sodium ethyl xanthate
Published in Environmental Technology Reviews, 2023
Ruixue Ma, Sikai Zhao, Xiaoyu Jiang, Yaozhong Qi, Tingting Zhao, Zhiyang Liu, Cong Han, Yanbai Shen
Froth flotation is one of the most popular operation processes in mineral beneficiation to realize selectively separating minerals based on their surface difference [1, 2]. During which, various chemical regents such as collectors, inhibitors, and regulators are usually used to control the properties of the mineral surface and the solution. Xanthates are regarded as one of the most common and effective collectors for the flotation of sulfide minerals [3]. Due to the chemical instability of xanthates, they are prone to decomposition in flotation pulp and aqueous solutions, and produce the toxic substance of CS2 or react with heavy metals to form chelates [4]. There are two destinations for the end-used water in the froth flotation process. One part of the wastewater is reused as recycled water after proper treatment. However, since the water quality determines the flotation performance, the recycled water usually contains residual oxidation products of the xanthate that will adsorb on the mineral particle surfaces and lead to the loss of inter-mineral selectivity [5]. The other part is the discharged wastewater, which will not only pollute the surrounding environment but also endanger people's health [6]. Therefore, the effective removal of xanthate from emitted flotation wastewater is essential.
Application and mechanism of a compound collector for the beneficiation of low-grade gold ore
Published in Particulate Science and Technology, 2023
Figure 5(b) shows the trapping performances of the four collectors at different pH values. The trapping capacities of the four collectors basically increase with the increased pH value and then tend to be stable. In general, the trapping capacities are better under weak alkaline conditions. PAX, SIPX and SIBX are all xanthate type agents, which are easily decomposed and unstable under acidic conditions, thereby reducing the trapping effects. While under strong alkaline conditions, such as pH > 11, the floatability of pyrite will be inhibited, thereby affecting the flotation effect. Under the weakly alkaline conditions, the stability of xanthate type agent is optimal and so is the recovery effect. ADD is a dithiophosphate type agent, which is more stable under acidic conditions and not easy to decompose. Under acidic conditions, ADD exists in a molecular state and the trapping effect is poor, while under weak alkaline conditions, the decomposition of ADD is promoted and the trapping effect is enhanced. Therefore, the flotation effects of the four collectors are better under the weakly alkaline conditions.
Current Status of the Effect of Seawater Ions on Copper Flotation: Difficulties, Opportunities, and Industrial Experience
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Constanza Cruz, Yesica. L. Botero, Ricardo I. Jeldres, Lina Uribe, Luis A. Cisternas
In the industrial flotation process, xanthates are commonly used as surface mineral activators. The effect of xanthate on the pyrite surface can be explained by Equations (1)–(3). These equations show the reaction mechanism of pyrite with xanthate. The theory of electrochemical adsorption of the collector has been considered to explain the redox reactions that occur in the chemical reaction. This electrochemical process involves different stages: (1) charge transfer in the adsorption of xanthate (); (2) oxidation xanthate to dixantogen (); and (3) formation of metal xanthate () (Mu, Peng and Lauten 2016).