Advanced Materials Research Vols. 962-965

Abstract: Both the single fluid and double-fluid method for water shutoff and profile control have their limitations. If the two kinds of working fluids are used in combination for water shutoff and profile control, each of them exhibits its own plugging capability while they can form plugging materials when they contact and react with each other. This method can be used as a plugging system in the formations, eliminating the low utilization ratio and huge waste of the single or double-fluid chemicals. It can enhance the plugging capability and improve the water shutoff and profile control results. The single and double fluid (SAD) system has been proved satisfactory in the field tests of conventional chemical water shutoff and profile control, high temperature chemical water shutoff and high temperature profile control and channeling-plugging in thermal recovery wells. The economic benefits are remarkable from the field tests of 14 wells.

Abstract: An improved particle swarm optimization (IPSO) is proposed for solving constrained numerical and engineering optimization problems in this paper. In proposed algorithm, an initialization strategy based on the opposition learning is applied to diversity the initial particles in the search space. Self-adaptive inertia weight is introduced to balance the ability of exploration and exploitation. Diversity mutation strategy is employed for best of particles to introduce diversity in the swarm space. Simulation results and comparisons with other algorithms using two benchmark constrained test functions and chemical engineering optimization problem are provided.

Abstract: The catalytic performance on HZSM-5/SAPO-34 catalyst in ethanol to propylene was tested in continuous-flow fixed-bed reactor. Coke on HZSM-5/SAPO-34 catalyst for ethanol to propylene was studied by O₂-TPO, N₂ isothermal adsorption–desorption and NH₃-TPD.The result showed that the strong and medium acid sites were the active centers of coke deposition; Coke mainly deposited in mesoporous and some coke blocked microporous orifice; In the initial stage of reaction, the high yield of propylene may be benefited from coke deposition, which adjusted the acidity and structure of HZSM-5/SAPO-34.

Abstract: With conductivity measurement in different concentrations of barium chloride, sodium sulfate, sodium chloride solution, their concentration-conductivity equation is obtained. Through mathematical conversion, the relation between sulfuric acid root ion in the solution, barium ion conductivity and the concentration is showed as: X=4.1744×10^-6Y-6.8544×10^-5,which is used to reflect the undissolved salt barium sulfate crystallization in the solution. Conductivity online measuring device is established, which can Intermittently test barium chloride, sodium sulfate solution of different concentrations, and detect the change of electrical conductivity in the process of crystallization of homogeneous barium sulfate in real-time. the different stages of crystallization process is determined by analysis of the conductivity curve. Through data processing to concert concentration into conductivity, so that the kinetic equation of barium sulfate crystallization process are obtained.

Abstract: Refinery units have the feature of operating inertia, long time transition period exists when production modes switch, during which product quality may decline and energy cost raises. The operating inertia have received significant attentions in actual refineries, while few literatures have given enough focus on it which is usually omitted to make scheduling easy. The core of this paper is to deal with the scheduling optimization problem of production modes switch considering operating inertia. By expression of the transition process, a mixed integer linear programming model was built based on a continuous time representation. The model optimizes unit operations by minimizing energy consuming. The formulation approach was used to address the scheduling of a refinery. Case study illustrates the model’s feasibility and efficiency.

Abstract: Grinding fitness caused by the failure of the steel ball filling rate, inappropriate steel ball matching, large steel ball size, etc. cannot meet follow-up flotation requirements. In order to optimize the ball grinding process, enhance the single separation degree of minerals and separation index, the steel ball diameter, steel ball matching and required additional balls of the mill are calculated with theoretical of ball radius formula and accurate filling ball method.

Abstract: Reduction of high-phosphorus titanomagnetite was studied for future comprehensive utilization of resource. Experimental temperature (T), burden alkalinity (CaO/SiO₂) and carbon-oxygen ratio (C/O) had an influence on the content of [P] and [S] in hot metal. Highest dephosphorization rate in hot metal appeared at C/O=1, high temperature was beneficial to desulphurization, but not for dephosphorization. High CaO/SiO₂ may decrease the content of [P] and [S]. C/O and CaO/SiO₂ had great influence on the content of [P] and [S] in hot metal.

Abstract: Blast furnace gas ash is one of the main solid wastes in iron and steel enterprise. The recovery of zinc from gas ash can result in considerable economic and environmental benefits. The effect of NH₃/NH₄⁺, L/S, [NH₃]_T and leaching time on the zinc leaching rate of blast furnace gas ash by using ammonia leaching process had been investigated in this paper. The results show that L/S and NH₃/NH₄⁺ are the main influence factors under the experimental condition. The optimal conditions for leaching process are: NH₃/NH₄⁺=2:1, L/S=4:1, [NH₃]_T =5mol/L, and the leaching time is 3 hours. The zinc leaching rate is 82.84% under the optimized conditions. The lead content in leaching solution is high, so the main task is to improve the removal rate of lead in the purification process.

Abstract: Pyrite cinders, which are the waste products of sulphuric acid manufacturing plants, contain hazardous but valuable heavy metals. This passage introduced that iron recovery by two-stage roasting the pyrite concentrate and gold-leaching from the pyrite cinder by thiourea. After re-floating and two-stage roasting of the gold-bearing low-grade pyrite concentrate, the final cinder contains about 0.056% As and 61% Fe and high grade gold and silver. The thiourea gold-leaching experiment for the pyrite cinder shows the gold-leaching rate is up to 90.4% in the case of grinding fineness of 60%-0.074mm, pH = 1~2, R=1:2, thiourea dosage of 10g / L, ferric sulfate dosage of 3g / L, leaching time of 6h.

Abstract: The Nongruri gold deposit is located in Mozhugongka, Tibet.There are two occurrence states of gold in Nongruri deposit, native gold and lattice gold. Fine grained native gold is hosted in clay minerals, and lattice gold just occupies little part. Gold particle size ranges from less than 0.001mm to 0.034mm, mainly in > 0.02mm, about 52.13wt% of total mount. According to the composition of mineral, occurrence state of gold and particle size measurement results of gold and gold-bearing mineral, it is a kind of fine-grained uneven refractory ore, and the recommended grind size should be smaller than-200 mesh.