Advanced Materials Research Vols. 201-203

Abstract: For producing high-value-added 823 shells steel used in military products ship, 50t electric arc furnace (EAF)-ladle furnace (LF)-continuous casting (CC) process was used in the test production. The results show that it is feasible to product the qualified 823 shells steel by controlling the final carbon and aluminum content, final deoxidization nitrogen fixation without titanium, controlling the superheat of the liquid steel in the tundish, spray water rate of mould, viscosity of mould powder and protection casting during the CC process.

Abstract: Zinc ferrite is usually formed during the roasting of zinc sulfide concentrate with high content of iron and reduces zinc recovery during the leaching of zinc calcine. Because it is difficult to find pure zinc ferrite in nature ore resources or in chemicals market, which impedes the investigation of the reaction characteristics of zinc ferrite and the seek of new technologies for zinc ferrite dissolution, so it is of significance to obtain relatively pure zinc ferrite for further research on zinc calcine leaching. This article investigated the preparation process of zinc ferrite based on the dissolution characteristics of a zinc calcine with 19.38% iron and put forward a method to judge the reaction end point during the leaching of zinc calcine to produce zinc ferrite. The results show that the product of zinc ferrite could be prepared through recovering the leaching residue during leaching the zinc calcine under the initial H₂SO₄ concentration equal to or larger than 160g/L, and that the leaching end point can be judged by comparing the experimental curve of Zn leaching with the zinc theoretical dissolvability curve.

Abstract: The manufacturing industry must have manufacturing systems that deal with the agile response to the appearance and changing conditions.As biological organisms are quite capable of adapting to environmental changes and stimulus, bio-inspired concepts have been recognized much suitable for adaptive manufacturing system control. This paper, therefore, proposes a NeuroEndocrine-Inspired Manufacturing System (NEIMS) using the potential field concept. The proposed NEIMS control architecture is inherited from neuro-control and hormone-regulation principles to agilely deal with the frequent occurrence of unexpected disturbances at the shop floor level. Hormone-regulation can impel system to be equilibrium through a potential field approach. From the cybernetics point of view, the control model of NEIMS has been described in detail. And a test bed has been set up to enable the NEIMS simulation.

Abstract: Heat furnace is one of the most important parts in iron and steel industry which is one of the basic industries. The control of furnace quality indices has a direct impact on iron and steel qualities and energy consumptions in an iron and steel manufacturing process. Due to dramatic changes of exhaust gas in combustion, this multi-variable process becomes time-varying, and also has inherent nonlinearities, couplings among the variables, large inertias and time delays.Therefore, manual operations are still being widely used in quality indices control. In this paper, an optimization control method is proposed for the control of furnace quality indices. The optimization consists of a materials temperature calculation model, an optimization objective, an ideal materials heating model and a furnace heating model. Optimization algorithm consists of the maximum principle, the simulated annealing algorithm，the iterative algorithm and sensitive analysis.Finally, quality indices were controlled by lower layer loop control on-line.The proposed optimization control method has been successfully applied to some steel plants. The industrial applications show the effectiveness of the proposed method.

Abstract: The leaching behavior of battery grade lithium cobalt oxide (LiCoO₂) was studied in Na₂SO₃-H₂SO₄ aqueous solutions with low H₂SO₄ concentration. The effects of H₂SO₄ concentration, leaching time, leaching temperature, and dosage of Na₂SO₃ on the leaching rate of LiCoO₂ were investigated. The experimental results show that all the cobalt in LiCoO₂ can be dissolved in the following conditions: the H₂SO₄ concentration of 0.4 mol/L, the leaching time of 0.5 h, the leaching temperature of 70°C and the Na₂SO₃ dosage being equal to the weight of LiCoO₂. It is proved that the leaching of LiCoO₂ in the system of Na₂SO₃-H₂SO₄ solutions is much more effective than that in other leaching systems. Moreover, the consumption of H₂SO₄ can be lowered greatly. Based on the leaching of pure LiCoO₂, the Na₂SO₃-H₂SO₄ leaching system is further applied in the treatment of spent Li-ion battery and the leaching rate of cobalt can be achieved as higher as more than 98%.

Abstract: Cu–Co–based alloys are the new generation of metal matrix for diamonds by powder metallurgy processed cutting tools. These alloys are created with the purpose of reducing the cobalt content in diamond tools. Cu-Co-based alloys matrix were fabricated using a hot pressing process at the temperature of 710°C , 750°С and 790°С by 15 MPa. Structures formed during sintering were studied by XRD and WDS. Micro-structural aspects were observed by EPMA. Densification, hardness, yield strength and compressive yield strength were performed. The results showed as follows: Cu-Co-based alloy matrix is composed by gray pre-alloyed particles, Cu-Sn binary solid solution, copper-rich phase and interface between particles and matrix; The higher sintering temperature, the more dendrite phase, in addition, the diffusion of carbon occurs; the holding force from matrix to particles becomes larger and the distribution of particles becomes more uniform; As the sintering temperature increased, the mechanical properties of Cu-Co-based alloy matrix enhanced.

Abstract: This study puts forward the technology of the precise reduction of micron-sized iron oxide: at lower temperature (＜1000°C), the high purity metallic iron can be reduced, separated and extract from iron ore, slag, the iron oxide in the dust which are in micron size. Precise reduction experiments are planned for high phosphorus hematite in Enshi, magnetite in Kazuo and the steel dust of a factory, in order to do the study on their reduction characteristics. According to the L16 (215) orthogonal test on high phosphorus hematite and magnetite, the result shows that: in the atmosphere of pure H₂ or 100% CO, the micron-grade mineral powder can be reduced at the condition of 650~850 °C; compared with the conventional particle size powder, the reduction temperature lowers about 300~350 °C in the same reduction degree. According to the L8 (27) orthogonal test on steel dust, the result shows that: by pure H₂ or 100% CO, the average metallization rate can reach 95% at the temperature of 900~1000 °C; the product of reduction keeps power state and its interparticle sintering does not occur, which means that it is reasonable to separate iron from other impurity elements through the physical method in the non-melting state.

Abstract: In this paper, orthogonal experiment design method was applied to determine the optimum condition for indium leaching from indium-poor zinc residue in HCl solution. Taking the results of range analysis and the situation of industrial production into consideration, the optimum conditions for conventional leaching are: reaction temperature 70°C, concentration of HCl 6 mol/L, leaching time 1.0 h, and ratio of liquid to solid 8:1. Under the optimum conditions, ultrasonic was used to enhance the leaching process. Compared with the conventional leaching process, this new process can provide better indium recovery, shorter leaching time, and faster leaching rate. The indium extraction of indium-poor zinc residue with ultrasonic treatment is up to 96 %, which is 31.0 % higher than that without ultrasonic treatment. In addition, the normal agitation improves the diffusion of solution in the ultrasonically enhanced leaching experiment.

Abstract: The leaching tests of nickel supported activated carbon under normal pressure in (NH₄)₂SO₄ were studied. The effects of experimental condition, such as initial concentration of (NH₄)₂SO₄, liquid-to-solid ratio, leaching time and leaching temperature on the leaching rate of nickel, were investigated. The results show that the leaching rate of nickel is 96.12% with initial concentration of (NH₄)₂SO₄ of 7.5%, liquid-to-solid ratio of 2, leaching time of 5h and leaching temperature of 25°C. The morphology of nickel supported activated carbon before and after leaching was characterized by XRD, which proved the effective separation of nickel and activated carbon. The leaching rate of nickel was also shown better at room temperature and atmospheric pressure. Moreover, it needn’t equipments enduring high-pressure and high temperature in the leaching process, thus reducing the costs of leaching equipments greatly. This work provides a new way to the comprehensive utilization of nickel-containing activated carbon.

Abstract: High-temperature properties of 10 samples of iron ore from Brazil, Australia and China were measured. Several conclusions were made based on these experimental results. Assimilability of Brazilian ore, Australian ore and Chinese ore concentrate were low, high and medium, respectively. Optimal fluidity of liquid phase was observed in 2 types of Brazilian ores (BR-B, BR-C), 1 type of Australian ore (AU-C) and 1 type of Chinese ore (CH-D). For self-strength of the bonding phase, Australian ore presented low levels, while Brazilian and Chinese ore presented high levels. According to the experimental results of high-temperature properties of iron ore, schemes of ore blending optimization were designed and sinter pot test using these blends were performed. The results indicated that ore blends composed of 30~45% Brazilian ores + 25~50% Australian ores + 20~30% Chinese concentrates presented excellent sintering results, considering both the performance of the processing and quality of the sinter. Therefore this experiment has proved that ore blending optimization combining high temperature properties can lead to more efficient sintering mixes.