Abstract The flotation experiments of Indonesia gibbsite ore were conducted using oxidized paraffin soap and tall oil as the collectors and sodium carbonate, sodium silicate and sodium hexametaphosphate as the regulators. Through the con-ditional experiments of multi-factors such as grinding fineness, collector and Regulator dosage and pulp concentration, the factors influencing the improvement of the silicon-aluminum ratio of gibbsite and the suitable flotation conditions were inves- tigated. The experiment results show that a flotation concentrate having a recovery of 63.49% and an aluminum to silicon ratio of 11.18 could be obtained at a grinding fineness of 75% -200 mesh, sodium carbonate dosage of 4000g/t, sodium silicate dosage of 2kg/t, sodium hexametaphosphate dosage of 250g/t , collector dosage of 700g/t and pulp concentration of 28. 57%. Bauxite is the main raw material for the production of alumina, refractory materials and building materials, with the rapid economic development, metal aluminum consumption will be increasing. With the sharp reduction of high-grade ore in bauxite, the use of beneficiation -Bayer method for medium-low-alumina-alumina is an effective method for producing alumina, which is to remove the silicon-containing minerals in the ore by using beneficiation method to obtain high-aluminum. Silicon is used as a raw material for the production of alumina by the Bayer process. At present, both domestic and foreign are exploring methods and processes for desiliconization of bauxite ore dressing. According to the chemical composition and crystal structure of bauxite, it can be divided into gibbsite, boehmite and diaspore. The bauxite has a molecular formula of Al 2 0 3 ·nH 2 O and is a hydroxide. Mainly formed in the exogenous weathering and deposition in the brown iron ore, carbon shale, clay mineral in close symbiosis with more impurities. The gibbsite, also known as alumite and oxyaluminum, has a molecular formula of A1 2 0 3 ·3H 2 O, and the crystal structure is layered. The hydroxide ions are packed into the hexagonal closest packing, and the aluminum ions are filled in the 2/3 octahedral space between the adjacent two layers of hydroxide ions to form a structural layer of the coordination octahedron. The structural layer is an ionic bond, and the structural layer is a molecular bond, and its layered structure determines its flaky morphology. Gibbsite is usually symbiotic with kaolinite, goethite, hematite, and illite. The gibbsite dehydration can be converted into boehmite, diaspore and alpha corundum , which can be replaced by kaolinite and kaolinite. Kaolinite is a main silicon-bearing mineral with a molecular formula of Al 4 (Si 4 0 10 )(OH) 8 . Because it contains aluminum, it will cause a small amount of aluminum loss when the kaolinite is removed by beneficiation. The methods of flotation include positive flotation and reverse flotation. Flotation generally use fatty sulfonates or bauxite flotation collector, the reverse flotation using an amine collector to, sodium hexametaphosphate, sodium silicate, soda and other tannin as a regulator. As early as the 1930s and 1940s, the United States used the flotation method to select the gibbsite bauxite in the Arkansas region, which could increase the aluminum-silicon ratio of bauxite from 3-8 to 10-19. The recovery rate is low. In the early 1970s, a mixture of tall oil, engine oil and oleic acid was used as a collector for gibbsite-type bauxite containing kaolinite and quartz . Sodium silicate and hexametaphosphate were used as regulators. The study of the recovery of gibbsite has the same low recovery rate [1] . The Weston et al. patent proposes that NaOH (or KOH), Na 2 CO 3 and dispersant sodium hexametaphosphate can be added to a ball mill for wet grinding, and the pH is maintained at 9.5 to 12.5 for slurry flotation, and satisfactory results can be obtained. . When the former Soviet Union processed the Vykopolsk bauxite mine in Ukraine, a mixture of Tal oil fatty acid and cationic agent AH lI-14 was used as a collector, and soda and 0II-7 type agents were added to make the ratio of aluminum to silicon. It is raised from about 5 of the original mine to about 9. The former Soviet Union used a sieve-washing-de-floating-flotation process for gibbsite bauxite. The ratio of aluminum to silicon increased from 4.7 to 9.00, and the recovery rate was 58.80% [2.3 J. V. V. Ishchenko [4] used the dodecylamine to reverse flotation of the ore with an aluminum to silicon ratio of 2.4 to 2.7 to obtain a concentrate with an aluminum to silicon ratio of >7. N. M. Anishchenko [5] succeeded in achieving the separation of chlorite and gibbsite using laurylamine. In recent years, China has mainly studied the flotation desiliconization of diaspore-type bauxite, but there is little research on the ore dressing of gibbsite-type bauxite. In the 1990s, the research on the separation of positive-floating aluminum-silicon was made, and the representative ones were selective grinding-selective agglomeration flotation separation process and stage grinding-floating separation process. According to the difference in grindability of various minerals in bauxite, some coarse-grain grade qualified products are obtained through selective grinding and classification, and the remaining narrow-grade materials are floated after de-sludge [6] . In view of the low hardness, low density, easy grinding and fine grain size of disulfide-embedded siliconite in China's diaspore-type bauxite, the bauxite reverse flotation research has been carried out in recent years [78] . In this study, the Sanshui bauxite mine in Indonesia was used as raw material, and the factors affecting the desiliconization by the positive flotation method and the suitable process conditions were discussed through the multi-factor conditions such as grinding fineness, collector and adjusting agent dosage and flotation concentration. I. Ore properties and test methods Indonesian gibbsite-type bauxite mainly contains aluminum minerals such as gibbsite. The silicon-containing minerals are mainly kaolinite and quartz, and contain hematite, titanium goethite and anatase. The mineral content and chemical composition of the ore are shown in Tables 1 and 2. The ore size composition is shown in Table 3. Table 1 Mineral content of ore Mineral name Gibbsite Kaolinite quartz Hematite Titanium goethite Anatase content 75 9 to 10 2 5 4 2 Table 2 Chemical composition of ore Mineral name SiO 2 Al 2 O 3 Fe 2 O 3 TiO 2 MgO CaO content 5.65 50.3 17.34 1.18 0.10 0.17 The ratio of aluminum to silicon in the ore is 8.67. In order to analyze the aluminum-to-silicon ratio of +200 mesh and -200 mesh, the original mine was divided into two grades of +200 mesh and -200 mesh using a -200 mesh sieve, and chemical analysis was performed separately. The analysis results are shown in Table 4. As can be seen from Table 4, the ratio of aluminum to silicon in the +200 mesh and -200 mesh grades in the ore is significantly different, and the ratio of aluminum to silicon in the +200 mesh class is more than 10. The flotation test adopts XFDl-63 single-tank flotation machine, the flotation tank capacity is 500mL, the flotation temperature is 32°C, the pulping time is 3min, and the flotation time is 10min. The test uses oxidized paraffin soap and tar oil as collectors, sodium carbonate, water glass, and sodium hexametaphosphate as regulators. Sodium carbonate is added during the grinding process. Second, test results and analysis (1) The effect of grinding fineness on the ratio of aluminum to silicon and recovery rate of flotation concentrate. The results of flotation tests for different grinding fineness are shown in Table 5. The amount of sodium carbonate is 5kg/t, the amount of collector is 0.5kg/t, and the concentration of pulp is 28.6%. It can be seen from Table 5 that the A1 2 0 3 grade and the ratio of aluminum to silicon of the flotation concentrate gradually increase with the increase of the grinding fineness, and reach the maximum value of 50.67% when the fineness of the grinding is 75%-200 mesh. And 10.92; when the fineness of the grinding is more than 75%-200 mesh, the grade of A12O3 and the ratio of aluminum to silicon of the concentrate begin to decrease. The recovery rate of concentrate A1 2 0 3 increases with the increase of grinding fineness. When the fineness of grinding is 92% of the content of 200 mesh, the recovery rate of A1 2 3 in the concentrate reaches 66.19%. It can be considered that when the fineness of grinding is from 75% to 200 mesh, the aluminum-containing minerals in the bauxite basically reach the monomer dissociation, and as the fineness of the grinding continues to increase, the gangue minerals are muddy, thereby making the flotation concentrate There are more gangue minerals in the mixture, resulting in a lower aluminum to silicon ratio of the concentrate. (2) The effect of sodium carbonate dosage on flotation. Under the conditions of grinding fineness of 75% to 200 mesh, different sodium carbonate flotation experiments were carried out. The test results are shown in Table 6. It can be seen from Table 6 that as the amount of sodium carbonate increases from 3000g/t to 7000g/t, the grade of concentrate A1 2 0 3 and the ratio of aluminum to silicon do not change much, and the grade of A1 2 0 3 ranges from 50.03% to 50.54%. The ratio is 10.52-lO.88; while the recovery rate of concentrate A1203 increases first and then decreases with the increase of sodium carbonate dosage, reaching a maximum of 64.07% at 4000g/t. Because the grade of concentrate Al 2 0 3 and the ratio of aluminum to silicon are not greatly affected by the amount of sodium carbonate, it is considered that sodium carbonate is mainly used to adjust the pH of the slurry, and the dispersion in the slurry is not obvious. The increased amount of sodium carbonate makes the collector more highly collectable under high alkaline conditions, thereby improving the recovery rate of concentrate A1 2 0 3 . Polycarbonate Embosssed And corrugated Sheet Polycarbonate embossed and corrugated sheet produced by our company has the characteristics of UV resistance, impact resistance, long service life and high light transmittance. The PC sheet models are: 840, 760. The length can be customized, the color can be transparent, lake blue, grass green, brown and so on. It is the ideal roof lighting material of environmental protection and energy saving for workshop lighting, greenhouse, canopy and car shed. Polycarbonate Embosssed,Blue Polycarbonate Corrugated Sheet,Brown Pc Corrugated Sheet,Good Waterproof Performance Pc Sheet SuZhou NiLin New Material Technology Co.,Ltd , https://www.sznlpc-sheets.com