Dian Wen Liu

Status and Prospect of Disassembly Process of Electronic Components on Waste PCBs

With the development and exhaustion of resources, the reclamation of secondary resources, especially urban mine, must be on the agenda. The major part of urban mine is waste printed circuit board (WPCB), and the effective processing of WPCB is depend on the disassembly. This article analyze the form of fastening, the method of fusion welding ,the recovery of welding and the disassembly of electronic component in process of disassembly, and point out the direction and tendency of development.

Research on Scandium Recovery and Extraction Process

Some methods and application status for Recovery of scandium and extraction of high purity scandium oxide from materials containing scandium were summarized . some corresponding recovery methods and extraction processes were suggested.

Application of Intensifying Secondary Concentration Technology in Reverse Flotation of Bauxite

In order to resolve the problem of fine particle flotation in the reverse flotation of bauxite. a new method of intensifying secondary concentration technology was firstly advanced, and author applied it to ore, achieved eximious experimentation index. The reverse flotation tests of intensifying secondary concentration aiming at bauxite from Guizhou province were studied. The results show that diaspore concentrate directly used in the Bayer-mineral processing method can be obtained by using the intensifying secondary concentration technology without pre—desliming. The average A/S of the concentrate is 10.28 with a recovery rate of 85.41%.

Influence of Pulp pH on Flotation of Fluorite and Calcite

Pulp pH value plays a significant role in the froth flotation. Especially in the flotation of fluorite, the performance of flotation will be affected greatly by pulp pH. MO, a new kind of modified fatty acid was used as collector, and H2SO4 and Na2CO3 were used to regulate pulp pH in the experiment. The mechanism of influence of pulp pH on flotation of fluorite and calcite was investigated by such parameters as fluorite recovery, zeta potentials and the infrared spectroscopy about minerals at different pulp pH values. As is shown in the results, the point of zero charge(PZC) of fluorite is pH=9.5 and the PZC of calcite is pH=8.5. The optimum pulp pH of the flotation of fluorite and calcite is determined as 9.5~10 and 8~9 respectively. pH value should be controlled above 9 to depress calcite. Finally, 9.5~10 was determined as the optimum pH to float the fluorite from the calcium-containing fluorite ores.

Flocculation and Sedimentation of Bauxite Flotation Tailings

Flocculation and sedimentation of fine bauxite from flotation tailing pulp were studied using different flocculants to investigate the possibility of its application. The results of this investigation indicate that inorganic flocculants of PAC and PAS have better flocculating effect than organic flocculants of PAM1# and PAM2# when keeping the original pH (7.5~8.0) of tailing pulp, however its consumption are large. It was found that the pH of pulp is important to the tailings settlement. The dosage of flocculants are greatly reduced and the velocity of floc settling is accelerated when the pH of tailing pulp is adjusted to 6.5~7.0 using sulfuric acid. PAM1# and PAM2# are effective flocculants for fine bauxite from the tailings pulp and improved the sedimentation performance compared with PAC and PAS at pH 6.5~7.0. It was also found that the flocculants can be used in combination to treat original bauxite tailing, and good sedimentation effect has been achieved, but the dosage of reagents is bigger when the organic flocculant is combined with inorganic flocculant.

Impact of Pre-Desliming on Flotation of Low-Grade Zinc Oxide Ore from Lanping

Zinc oxide ore from Lanping contained large amount of fine slime which badly deteriorated flotation performance, and it complexly intergrowed with plenty of alkaline gangues with calcium and magnesium. In order to investigate the impact of pre-desliming on flotation, experiments of direct flotation and pre-desliming flotation were carried out in the work. Finally, a zinc recovery of 88.73% with a Zn grade of 13.93% was obtained in direct flotation test, and a higher zinc recovery of 95.25% with a Zn grade of 13.56% was achieved by pre-desliming flotation. Pre-desliming flotation test was superior to direct flotation test, because of an increase of nearly 7% in zinc recovery under the condition of similar Zn grade. At the same time, dosage of sulfurization agent used in pre-desliming flotation was lower by 46.67% than that in direct flotation, which obviously improved the availability of sulfurization agent. So both product index and economic benefit were enhanced after pre-desliming.

Influence of Important Factors on Ammonia Leaching of Alkaline Zinc Oxide Mineral

The effects of refractory zinc oxide ore which came from Lanping of Yunnan Province were studied using agitation leach method in laboratory in order to find out the optimum leaching conditions. The optimum conditions obtained are as follows: ammonia concentration 3mol/L, ammonium bicarbonate 1.5mol/L, granularity (-0.074mm) about 85%, solid to liquid ratio 4:1, and leaching time 2h. On this condition, the test obtained the better index of the zinc leaching rate 74.4%.

MCGS Software of Industry Control and its Automation Application

The composition construction and characteristics of MCGS configuration software of industry control are introduced，the process of configuration with MCGS and main functions of the system is also described in details through the project study on grinding and classification system in mineral processing plant．Plant experiences show that the system has the advantages of high stability, high automation，convenient operating，and the system has widely the value of application and promotion．

Research on Balling Properties of Pyrite Cinder with High Content of Copper

The balling properties of pyrite cinder (PyC) with high content of copper are researched in this paper. The results indicate that grinding process is an effective way to improve the quality of green balls. Through the measuring of drop strength compressive strength and cracking temperature on pyrite cinder balls, it is found that the best bailing properties of PyC can be obtained under the recommended parameters (the content of grain size of PyC below 75 μm accounts to 95.75% and bentonite dosage is a mass ratio of 2%) and green balls with 5.4 frequency•(0.5m)-1 of drop strength, 15.8 N•each-1 of compressive strength and cracking temperature of about 700 °C are obtained, which can meet the requirements of metallurgical technology.

Research on Properties and Flotation Feasibility of a Silver Ore Associated with Copper in Yunnan

Properties of the ore were studied by chemical analysis, X-ray diffraction analysis and optical microscopy analysis. Research results show that the ore contains 479.5 g/t of silver and 0.54% of copper. Silver minerals are mainly argentite, copper minerals are mainly chalcopyrite and digenite, and gangue minerals are mainly quartz and dolomite. Based on the properties of the ore, flotation feasibility study was conducted. Results show that concentrate with excellent test indexes that a Ag grade of 4787.31 g/t with a Ag recovery of 87.97% and a Cu grade of 6.01% with a Cu recovery of 87.92% were obtained under the used process and reagent system conditions.