Advanced Materials Research Vols. 690-693

Abstract: This study discussed the effects on leaching rate of from low-grade manganese ore using three reductants (Hydrogen peroxide, Glucose, Cellulose). The results showed: great increase of extracting rate can be obtained in the process of leaching by adding a small amount of reductant. the leaching rate of two valence manganese can reach a maximum of 90.76%, using hydrogen peroxide as the reductant.

Abstract: Depressurization method is a more potential way for gas production from gas hydrates. The behavior of gas hydrates dissociation by depressurization method is observed by the use of an experimental apparatus. The hydrates saturation is tracked by TDR during hydrates decomposition. The decomposition process consist three stages: fast dissociation, stable dissociation and the end. Significantly one of major factors that determine gas production rate by depressurization: degree of depressurization is discussed. t1/2 is used to characterize the hydrates decomposition rate. The greater of degree of depressurization is the faster of the hydrates decomposition rate gets.

Abstract: Under acid leaching conditions, studies was discussed that the impacts of reductant type and amount on leaching rate of manganese by using three groups of glucose - hydrogen peroxide, cellulose - hydrogen peroxide and glucose - cellulose as composite reductants. The results indicate that compound reductant is able to improve the leaching rate of manganese easily. With the optimal reductant group, leaching rate of manganese can be more than 97%.

Abstract: In order to make a research on all the factors which influence the dissolution rate of the rock salt, this article study on how the temperature, concentration of the rock salt solution, the dissolution obliquity, and the velocity influence the rock salt dissolution rate. The experiment shows that, all the factors make strong influences on the dissolution rate as follow: ⑴ when the obliquity is 180°, the dissolution rate is the largest, and the 0°is the smallest. The dissolution rate increases with the increasing of the obliquity. ⑵ the dissolution rate increases with the concentration to the largest and then insoluble in saturation.⑶ the dissolution rate increases with the temperature increase. ⑷At first, the dissolution increases with the velocity of the flow, then decreases to stabilize.⑸ This article also integrates the relationship between the temperature, obliquity, velocity and the dissolution rate, and the research result will play a key role in the production of cavity and the numerical simulation in the production procedure.

Abstract: Vibrating lamella thickener (VLT) developed by Kunming University of Science and Technology is a new generation of inclined plate settling device, and in this device such long-standing problems in traditional lamella thickener (LT) as material bonding and blockage between channels in inclined plates, material deposits and blockage in cone bucket, as well as unsteady discharging of high solids underflow, etc. are effectively resolved, through periodic vibration of inclined plate modules, the use of built-in device for removal of deposited material on cone wall and of forced discharging device for high solids underflow. Paste discharging is now a new way for the effective treatment of tailings in recent years, due to its superiority for mining safety and environmental protection. The industrial tests for paste thickening of iron tailings were carried out in a mineral processing plant of Mining Co., Ltd. of Panzhihua Iron and Steel Group, using a ZXNQP-32 VLT. In the test the size distribution and settling characteristics of the tailings were analyzed, and the main operating parameters in the VLT were tested under the natural settling and flocculated settling conditions, respectively. The results of test indicate that the solids concentration of underflow from the VLT is capable of reaching higher than 70%; meanwhile, the solids content in overflow from the VLT is as low as less than 300 mg/l while flocculant is added in the ore pulp for pretreatment and such an overflow can be directly discharged into environment or be recycled in the plant. It is thus concluded that VLT is effective for paste thickening of iron tailings.

Abstract: Through a large number of laboratory tests, authors study corrosion effect of acid rain on the technical properties of mineral aggregate, such as apparent relative density, bulk relative density, crushing value and Los Angeles abrasion value. According to the tests results, the degree of acid corrosion of mineral aggregates constantly increases with the decreasing of the PH value and the increase of dry-wet cycle number. The acid corrosion resistance ability of mineral aggregates is the best for the granite, medium for basalt and the worst for limestone.

Abstract: Orientation data of discontinuities are of paramount importance for rock engineering studies because they affect the rock slope stability and control the path of flow. Most orientation data are collected using linear sampling. However, data acquired by such linear sampling techniques are subject to bias, owing to the orientation of the sampling line. Even if a weighting factor is applied to orientation data to reduce this problem, the bias is not be significantly reduced when certain sampling orientations are involved. If the linear sampling orientation nearly parallels the discontinuity orientation, most of these parallel discontinuities are excluded from the survey results. To correct this bias ,a weighting factor is applied to orientation data first of all and then the orientation data in blindzone is corrected by added date from the different sampling line .The comprehensive pole and contour plots diagram is completed at last, which is consistent of the real situation. This method makes up for the deficiency of linear sampling technique and obtains the comprehensive orientation data in rock.