| Gallium is an important rare metal mineral element and it is one of the important basic materials in the field of electronic industry. Gallium is scattered in bauxite and other ores in the form of a trace. In the world,more than 90% of the native gallium is extracted in the process of alumina’s production. However, the extraction of gallium is very difficult and the accompanying relationship of it is very complex, so it is very difficult to increase its yield by a large margin,even though price of gallium rises. The number of metal gallium will be scarce seriously in the next 20-30 years if we can not improve the recovery rate. It is particularly necessary for the efficient recovery of gallium in bauxite to study the occurrence regularity of gallium in bauxite. The conventional experimental method that focus on the occurrence regularity of gallium in bauxite is very limited. With the rapid development of computer technology, algorithm and force field are improved gradually. As a tool that contains both theoretical study and experimental determination, the method of molecular simulation has enormous advantage in the field of micro system. Therefore, the method of molecular simulation has beenused widely on occurrence regularity.This paper mainly adopts the technique of molecular simulation,which uses quantum mechanics, molecular mechanics and Monte Carlo method to simulate and calculate.It focuses on researching the change rules of three kinds of mineral crystal diaspore, boehmite and gibbsite after the corresponding aluminum are replaced by gallium and the adsorption behavior of gallium oxide in diaspore(011)polyhedron,boehmite(110) polyhedron and gibbsite(010) polyhedron. The results are as follows:(1) Using Accelrys Materials Studio molecular simulation software to build the models of ore mineral crystal structure in bauxite: diaspore、boehmite and gibbsite and optimizing them based on quantum mechanics,then comparing the changes of cell parameters between before and after optimization to get rational crystal models.(2) Using the method of molecular mechanics to simulate the gallium replacing the aluminum of diaspore 、 boehmite and gibbsite,respectively. It can be found that the total energies of three kinds of mineral systems are greatly reduced, and the system is more stable after the Forcite optimization. The order from big to small of change in the range of alternative energy system before and after is diaspore, gibbsite and boehmite. It implies the phenomenon that gallium replaces aluminum in hard diaspore monohydrate is more likely to happen.(3) Using the method of Monte Carlo molecular simulation to calculate the regularities of adsorption gallium oxide on hard diaspore monohydrate(011) polyhedron, boehmite(110) polyhedron and sanshui diaspore(010)polyhedron in the depth of 0, 300, 600 and 900 m,respectively. The results show that the adsorption quantities of gallium oxide in three kinds of minerals change little with the different depth;boehmite which is abundant of aluminum can adsorb the most gallium oxide among these three kinds of mineral, it maybe has relationship with active group sections of aluminum.(4) Using Monte Carlo molecular simulation method to simulate and calculate the competitive adsorption of titanium oxide, iron oxide and gallium oxide in diaspore(011) polyhedron, boehmite(110) polyhedron and gibbsite(010) polyhedron, respectively, which occurs under the condition of this: the polyhedron temperature of thermodynamics is 307 k and the pressure is 4.6MPa. Comparing the changes of adsorption capacity and adsorption energy, we can obtain that TiO2 and Ga2O3 whose competitive adsorption is stronger have a greater influence on the adsorption of gallium oxide. |
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