Xiong Tong

Beneficiation of Cassiterite Fines from a Tin Tailing Slime by Froth Flotation

The beneficiation of cassiterite fines from a tailing slime in the Datun concentration plant was studied through a froth flotation process, with the chemical scheme of benzohydroxamic acid as collector, lead nitrate as activator, and pine oil as frother. It was found that tin values are mainly contained in the fine fraction of the sample and cassiterite is mostly associated with iron minerals and calcium minerals, so that the desliming treatment and the addition of dispersants and depressants can not be used as it generally results in the undesired loss of tin values. A novel flotation process with no dispersant and depressant as well as no desliming was developed. It showed that this process was effective in recovering the tin values from the tailing slime assaying 0.18% Sn, and produced a concentrate assaying 3.5% Sn with the recovery of 74.16%. It has been found that pine oil played a significant role in improving the recovery for tin values.

The Adsorption of Cu Species onto Pyrite Surface and Its Effect on Pyrite Flotation

The adsorption of Cu species onto pyrite surface and its effect on flotation were investigated by using microflotation tests, first-principle calculations, and XPS surface analysis. The results indicated that the flotation of pyrite appears to be activated with CuSO4 only at alkaline pH, while being depressed at acidic and neutral pH. The adsorption of copper ions on pyrite surface was pH-dependent, and the adsorption magnitude of copper ions at alkaline pH is higher than that at acidic and neutral pH due to a strong interaction between O atom in Cu(OH)2 and surface Fe atom except for the interaction between Cu atom and surface S atom. At acidic and neutral pH, there is only an interaction between Cu atom and surface S atom. The adsorption was relatively weak, and more copper ions in solution precipitated the collector and depressed the flotation of pyrite. XPS analysis confirmed that more copper ionic species (Cu(I) and Cu(II)) are adsorbed on the pyrite surface at alkaline pH than that at acidic and neutral pH.

Beneficiation of Cassiterite and Iron Minerals From a Tin Tailing with Magnetizing Roasting-Magnetic Separation Process

The beneficiation of cassiterite and iron minerals from tin tailings with magnetizing roasting and low-intensity magnetic separation (MR-LMS) process was studied in this work. It showed that the process was effective in recovering the tin and iron values from the refractory ore, produced a high-quality iron concentrate assaying 64.68% Fe with the recovery of 87.47% and a tin-rich middling assaying 4.10% Sn with the tin recovery of 63.55%, from the tin tailing assaying 0.20% Sn and 14.56% Fe. It has been found that the key point of the process was the step of magnetizing roasting, which converted hematite and limonite into magnetite. The separation efficiency of the process closely correlated with roasting temperature, roasting time, lignite addition, and the liberation of cassiterite with the iron minerals.

Flotation of Indium-Beard Marmatite in the Low Alkali Conditions

Flotation of indium-beard marmatite from Mengzi multi-metal sulfide ore in the low alkali conditions was studied. It shows that the mixed reagent X-41 (Main chemical components: Cu≧12%, S≧18%, O≧48%, H≧4.5%) as a new activator in the flotation at pH 9.5 produced a much better beneficiation than the copper sulfate at pH 13. The grade of zinc and indium was increased by 3.39% and 53.52g/t respectively, while the recovers were increased by 4.57% and 3.54%.

Study on Flotation of Lead-Zinc Oxide Ore from Yunnan

With regard to a deep-extend oxidized refractory lead-zinc ore from Yunnan province, containing 4.55% Pb and 17.09% Zn, a test study was carried out. By adopting single-stage roughing, single-stage scavenging, two-stage cleaning in the flotation of lead oxide ores, and single-stage cleaning, single-stage cleaning in the reverse flotation of zinc oxide ores, bulk concentrate of lead and zinc containing 36.60% Pb, 19.63% Zn with the Pb recovery of 82.45%, zinc concentrate containing 36.52% Zn, 0.44%Pb with the Zn recovery of 73.18% were obtained in the closed circuit experiment.

Recovery of Fine Cassiterite from Tin Tailings Slime by Froth Flotation

Tin gravity slime tailings of Datun mineral processing plant in south-eastern China contains fine and ultrafine cassiterite. Tin recovery from the slime tailings was studies in the presence of different flotation reagents. A flotation process has been used on a laboratory scale to investigate the effect of various reagents such as collectors, auxiliary collector, activators, ect., and theirs dosages in neutral flotation environment. To reach an optimum tin recovery, different dosages of the reagents were also studied. Due to cassiterite is friable and a large amount of fines and slimes were generated. Usually de-sliming is used to prevent slime coating and to increase the recovery of tin. However, analyses have shown that fine particles in the sample mostly contain tin, thus de-sliming was not suggested. By applying the process, ultrafine cassiterite can be efficiently recovered from the tailings slime by one rougher process, and the concentrate assaying 1.20% Sn with a recovery of 89.10% was obtained.

Flexible Distributed Workflow Management Systems Design Based on CORBA

The paper addresses the problem of flexible Workflow Management Systems (WFMS) in distributed environment. Concerning the serious deficiency of flexibility in the current workflow systems, we describe how our workflow system meets the requirements of interoperability, scalability, flexibility, dependability and adaptability. With an additional route engine, the execution path will be adjusted dynamically according to the execution conditions so as to improve the flexibility and dependability of the system. A dynamic register mechanism of domain engines is introduced to improve the scalability and adaptability of the system. The system is general purpose and open: it has been designed and implemented as a set of CORBA services. The system serves as an example of the use of middleware technologies to provide a fault-tolerant execution environment for long running distributed applications. The system also provides a mechanism for communication of distributed components in order to support inter-organizational WFMS.

Investigation on the adsorption behaviour of heating-treated starch on hematite

ABSTRACT An investigation on these adsorption characteristics of heating-treated starch on fine hematite was conducted through a series of tests, like adsorption tests, zeta potential tests, micro-flotation tests and Fourier transform infrared spectroscopic analysis as well. All results pointed out that different temperature of starch heating treatment tends to achieve different degree of starch gelatinization, probably contributing to its different flocculating capacities on mineral surfaces. Since such differences on the degree of starch gelatinization after heating-treatment seem to induce distinct amounts of adsorption densities and flocculated recoveries on hematite. And the higher the water temperature is, the better the starch gel would be.

Activation of Sphalerite by Ammoniacal Copper Solution in Froth Flotation

The activation of sphalerite particles by ammoniacal copper solution (ACS) was investigated in this study. This microflotation study was conducted on a single sphalerite mineral with the particles size of 38 μm to 75 μm. Results showed that ACS has somewhat better activation effect than copper sulphate (a traditional activator) with sodium isobutyl xanthate as the collector. Agglomeration observation, contact angle measurement, and X-ray photoelectron spectroscopy measurement results of sphalerite particles verified the superiority of this new activator. Therefore, the substitution of copper sulphate with ACS would increase the separation efficiency not only in marmatite flotation but also in sphalerite flotation.

Extraction of vanadium in the comprehensive recycling of spent Al2O3-based catalyst

Under the premise of comprehensive recycling valuable metals, a novel technology was developed to extract vanadium from spent Al2O3-based catalyst. Mixture of spent catalyst and sodium carbonate was roasted at 1000°C for 30 min with the mol ratio of Na2O to (Al2O3 + V2O5 + MoO3) as 1.15, after water leaching, 97.3% of vanadium could be extracted. With CaO addition of 25 g/L and reacting at 90°C for 4 h, 98.6% of vanadium in sodium aluminate solution was precipitated as desilication residue. The desilication residue was leached at 80°C for 45 min with sodium bicarbonate concentration of 100 g/L and L/S of 4 mL/g, over 96.4% of vanadium could be leached. By two purification steps with addition of 30 wt.% H2SO4 and Mg(NO3)2, respectively, over 99% of Al, 96% of Si, 93% of P and 95% of As were removed from leach liquor. Adding 50 g/L NH4NO3 to the purified leach liquor and adjusting pH to 8.2, 99.8% of vanadium could be precipitated as ammonium metavanadate. After calcination, the purity of V2O5 product was 98.25%. In the whole process, up to 88.7% of vanadium could be recovered from the spent catalyst.