Radioactivity Old Nepheline Syenite Comprehensive Utilization

Gejiu nepheline syenite is the kind of mineral resources in a dozen high potassium, but also the highest level of geological work in China, the deepest level of processing technology of deposits, mineral exploration in the first paragraph probe was5000million tons of ore reserves for industrial production and construction resources to provide a full guarantee. If exploitation can lead metallurgy, chemicals, building materials industry joint development, the formation of a new pillar industry in southern Yunnan region, but the early geological work in the old nepheline resources preserved drill core samples, according to a new standard for inspection of radioactive nuclides, we found that in addition to the ore contains a considerable amount of radioactive elements uranium, thorium, but also contains a high radioisotope K40, and K40of radioactivity up to3000Bq/Kg.In order to clarify Gejiu nepheline syenite processing, the intensity of radionuclide specific activity of radionuclides in the process and the process of direction and changes of use in this paper states " the classification of radioactive waste " standard, the state who receive long-term exposure to radionuclides in the human body to accept the use of the standard radiation dose, and the analogy of our existing radioactive rare earth mining and processing of evaluation criteria, the Gejiu nepheline syenite deposit, and the specific activity of radionuclides the study of health hazards, at the same time the whole process flow pilot study. Focus on the process of: preparation, firing, stripping, removal of silicon, carbon points, calcined alumina output. Sample of the feed material samples with a specific activity of radioactive nuclide identification, according to test results to determine the radionuclide in the process of the processing behavior and direction, the conclusion is as follows:(1) Gejiu nepheline syenite deposits are the main radionuclides210Pb,238U,235U,232Th,226Ra,40K and137Cs seven kinds, regardless of the total radioactivity by the ore, the radioactivity of the individual radionuclide, tolerance of human exposure to radioactive continuous measurement standards, and even cement in accordance with the provisions of the state’s internal and external exposure indicators to measure, old nepheline syenite deposits belong to the low radioactivity of resources, do not need protection;(2) Gejiu nepheline syenite deposits of radioactive intensity and distribution of radioactivity, according to generally verify the pre-measured total gamma conclusion that, in the surface and along the depth, most regions are radioactive intensity of the normal zone, radionuclides and radioactive intensity anomalies, was isolated point-like distribution;(3) Ore processing process, the intermediate material and the total radioactivity radioactivity, failed to meet minimum security standards for radioactivity, which nepheline sintering process is not the whole process of radioactive protective measures to be taken, the product of alumina radioactivity is not high, normal metallurgical products, sodium carbonate, potassium carbonate, total a were2.75×103and3.33×104, are far below the GB9133-1995low-level radioactive waste total a=4×106requirements requirements, are not normal to be protective chemical products; Products within the cement according to index I Ra of0.69to0.75, according to index I y outside the0.89to0.95, in line with national requirements for building and furnishing materials I Ra≤1.0and I γ≤1.0standard, can be used as the main material for building use, use of unrestricted. Normal cement products;(4) Ore processing process, the radionuclides to vary, in which the most important radionuclides of uranium, thorium, radium and potassium to determine the intermediate and final products of radioactive material intensity variation:①uranium, after firing, dissolution, about half of the slightly weaker retained in nepheline mud to enter the cement system and eventually into the cement product; about half of the slightly stronger into the solution, the solution of uranium in the de-silicon and carbon sub-processing, retained most of alkali in the solution and into the system, soda, about3/4into the potash products,1/4into the sodium carbonate products;②radium, after firing, dissolution, about3/4retained in nepheline mud to enter the cement system and eventually into the cement product; only about1/4into the solution, the solution of radium in the removal of silicon, carbon sub-processing, but most retained in solution into the alkali systems, soda, about3/4into the potash products,1/4into the sodium carbonate products;③thorium, after firing, dissolution, about1/3of remaining in nepheline mud to enter the cement system and eventually into the cement product; about2/3into the solution, the solution of thorium in the removal of silicon, carbon sub-processing, retained most of alkali in the solution and into the system, soda, about3/4into the potash products,1/4into the sodium carbonate products;④40K, after firing, dissolution, nearly90%of the dissolved solution, the solution of40K in the de-silicon, carbon sub-processing, but most retained in solution into the alkali systems, alkali, about92%into the potash products,8%dispersed in sodium carbonate product.Main innovation of this paper are:deposits of nepheline syenite for radiationresearch, specifically in the ore that may arise during the use of radioactive impact, as nepheline provide the basis for resource development. According to both the specific activity of radionuclides measured results to determine the radionuclide in the process of dealing with the behavior of the process and direction, a clear process of ore processing, the intermediate materials (including liquid material and solid material), the main radionuclides factors, and determine its specific activity and total radioactivity of the process in which some of the processes needs to be done and what kind of radiation protection level of protection, given the clear conclusion,this paper to complete utilization of nepheline syenite for the resources to provide a guarantee.