MUHARREM TÜMUÇIN (TR)
NURİ, SARIOĞLU (TR)
BEYHAN ÖZDEMIR (TR)
BARKIN MINEZ (TR)
| GB191417311A | 1915-08-12 | |||
| US2373123A | 1945-04-10 | |||
| US2831574A | 1958-04-22 | |||
| US4171261A | 1979-10-16 | |||
| US4147614A | 1979-04-03 | |||
| US3936372A | 1976-02-03 | |||
| CA1064863A | 1979-10-23 |
| CLAIMS 1. A magnesite ore (MgC03) enrichment process, comprising the steps of mixing the magnesite ore with an alkaline solution and thus removing Si02 compound contained therein, and washing and drying the enriched ore. 2. A magnesite enrichment process as in Claim 1, comprising the step of crushing the magnesite ore into small particles of between 1 - 30 mm. in size before being passed through the alkaline solution. 3. A magnesite enrichment process as in Claim 1 and 2, comprising the- steps of subjecting the magnesite ore to magnetic field thereby separating the magnetic components therein and decreasing the Si02 ratio to between 0.5 - 2 %. 4. A magnesite enrichment process as in any one of the above claims, comprising the step of mixing the magnesite ore with the chemical solution at a ratio of 5/1, 10/1 and 20/1 depending on the Si02 ratio that is contained therein. 5. A magnesite enrichment process as in any one of the above claims, comprising the step of heating the alkaline solution. 6. A magnesite enrichment process as in any one of the above claims, comprising the step of keeping the magnesite ore in the alkaline solution for a period of time. |
Technical Field
The present invention relates to the enrichment of magnesite ore. Prior Art
Magnesite is a carbonate depicted as MgC0 3i theoretically comprising 47.8 % MgO and 52.2 % C02. It is a natural ore used as raw material in the production of heat resistant, basic refractory and oven materials needed mainly in industries requiring high heat like iron-steel industry, cement industry, lime industry and non-ferrous metal industry. This ore is also used in the chemical industry and pharmaceutical industry in the preparation of various reactives and drug products.
Its color varies between white, yellow or grey and brown. In nature it is formed in two forms, being cryptocrystalline (gel/amorphous) and crystalline (macrocrystalline). The quality of the ore increases or decreases according to the amounts of impurities contained. In nature, it is very hard to find magnesite with the required characteristics that are suitable for areas of utilization. Any foreign element contained in magnesite with an extent of more or less than 0.1 % determines whether or not magnesite can be considered economically viable with the present technology. The natural magnesite ore contains the impurities such as Si0 2 , CaC0 3 , A1 2 0 3 and Fe 2 0 3 . The amount and ratio of impurities contained in the ore determine the quality and sale price of the ore.
The magnesite technology starts with the production of the ore from the mineral deposit. The ore produced from the mineral deposit generally by surface mining methods and seldom by underground mining methods is in general subjected to an enrichment process. The enrichment process is realized by removing gangue materials from the ore.
In order to perform the optical enrichment, a widely used enrichment process, the enclosing rocks should differ from the ore in terms of color. In order for the other enrichment process, which is magnetic enrichment, to be effective the ore and/or the enclosing rocks should have magnetic properties. The above-mentioned processes cannot be used in ores that do not have distinctive color, density and magnetic feature differences. The chemical enrichment method is applied in conditions wherein these processes are not suitable. In the state of the art United States Patent Document No. US3936372, the process of magnesite ore enrichment is explained wherein the ore, according to the magnetic separation method, is first turned into powder by being burned, then subjected to abrasive crushing for the separation of the gangue therefrom.
In the state of the art Canadian Patent Document No. CA1064863, it is disclosed that the magnesite ore is enriched chemically by being passed through a solution containing ammonium and alcohol. The Aim of the Invention
The aim of the present invention is the realization of the easy and low-cost enrichment of magnesite ore.
Summary of the Invention
The magnesite ore to be used in the magnesite enrichment process, realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, reacts by being passed from an alkaline solution and the Si0 2 rate of the ore is decreased by enabling the silicon dioxide constituents contained therein to pass to the solution.
In an embodiment of the present invention, in order to be enriched the magnesite ore is kept in a liquid solution which contains alkalis like KOH, K 2 C0 3 , NaOH, Na 2 C0 3 , Na citrate, sodium stearate and which is heated to temperatures between 40°C to 90°C. The impurities in the ore react with the chemical solution and the Si0 2 containing compounds bonded thereto are removed from the ore. The process can be used in magnesite ores containing Si02 in ratios between 0.2 % - 5 %. The Si02 content in the ores is reduced by 40 % - 80 % by this process. In this process cost and facilitation advantage is provided with respect to the present chemical enrichment processes. The most important advantage of this process is that it can be applied to 1 - 30 mm. particle sized group without fine grinding the ore to be enriched and is the distinctive characteristic of the process with respect to conventional chemical enrichment processes.
The process of the present invention not only has cost and facility advantage over conventional chemical processes, but it can also be applied to high tonnages of ore. Detailed Description of the Invention
The magnesite ore (Magnesium carbonate, MgC0 3 ) is a mineral having a structure of minute crystals (cryptocrystalline) and large crystals (macrocrystalline) and contains at least some of the various impurities (iron, calcium, aluminum and silicon dioxide (Si0 2 )), carbon dioxide (C0 2 ) and magnesia (MgO).
The magnesite enrichment process comprises the steps of mixing the magnesite ore with an alkaline solution and thus removing Si0 2 compound contained therein, and washing and drying the enriched ore.
Not only the content of magnesia (MgO) but also the amount and ratios of other impurities have important effects on the quality of magnesite. The ratio of CaO/Si0 2 is an important factor for magnesite quality and the molecular ratio is required to be around 2. In order to increase the ratio of CaO/Si0 2 , Si0 2 is enabled to be removed from the magnesite ore. The alkaline carbonates and hydroxides are ionized in water and react with Si02 contained in the ore, and thus Si02 is removed from the ore structure. Parallel to this decrease, the ratio of CaO/Si0 2 is enabled to be increased and thus the magnesite ore is enabled to be enriched and made suitable for refractor production.
The magnesite ore containing Si0 2 as impurity reacts with the alkaline solution as shown below: Alkali + Magnesite Ore Enriched + Na 2 Si0 3 + C0 2 + H 2 0
NaHCO- Magnesite Ore
(MgC0 3> Si0 2> C0 2 )
Na 2 C0 3 (MgC0 3 )
NaOH
In an embodiment of the present invention, the enrichment process comprises the step of crushing the magnesite ore into small particles before being passed through the alkaline solution. The ore is broken and crushed by for example jaw or cone crushers so that the alkaline solution penetrates into every part of the magnesite ore. The particle size being in the interval of 1 - 30 mm. is sufficient for the solution to penetrate into the ore.
In an embodiment of the present invention, the magnesite ore is subjected to magnetic field thereby separating the magnetic components therein and contains Si0 2 compound that is decreased to a ratio of between 0.5 - 2 %. The magnesite ore that also contains magnetic impurities in its natural form is cleansed of the impurities with magnetic features contained therein by being first subjected to the magnetic field. Thus, the Si0 2 that is bonded to the magnetic component in the ore is decreased to a certain level and made ready for the application of the enrichment process.
In an embodiment of the present invention, the magnesite ore is mixed with the chemical solution at a ratio of 5/1, 10/1 and 20/1 depending on the Si0 2 ratio that is contained therein. For example, it is sufficient to mix 100 gr. of ore having 3% Si0 2 with 500 ml. of chemical solution.
In an embodiment of the present invention, the magnesite ore is mixed with heated chemical solution. Thus, the solution is enabled to react with the ore more effectively. In an embodiment of the present invention, the magnesite ore is kept in the chemical solution for a period of time. For example, the ore is kept in the solution for 30 minutes, thus it is ensured that the solution completely reacts with the ore.
After the mixing process, Si0 2 is removed from the ore as Na 2 Si0 3 with the solution as a result of the above reaction. The chemical in the solution that does not react can be used again after the waste portion is filtered.
The process of the present invention can be directly applied to the ore. The ore does not have to be fine grinded, and coarse grained ore can be used. Thus, no grinding or re-briquetting cost incurs. Both cost and ease of utilization advantages are provided in industrial applications of high tonnages.
It is to be understood that the present invention is not limited to the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection postulated by the claims of the present invention.