| As a secondary resource,tailings sand has been paid more and more attention,especially the comprehensive treatment and regeneration of tailings sand.In addition to Japan,Germany,Sweden and other countries to fully exploit the development of tailings sand,the comprehensive utilization of tailings sand has also been valued in other developed countries,such as the Soviet Union,Canada,the United States.China has also made some progress and achievements in the development and utilization of tailings,but its utilization rate is very low compared with foreign countries.Therefore,the comprehensive utilization of tailings sand is necessary for saving resources,improving the environment and achieving sustainable development of the mining economy.Lead-zinc tailings sand concrete is a new type of radiation-proof concrete material.Based on ordinary concrete,lead-zinc tailings sand is used as fine aggregate,and ordinary sand is mixed into concrete according to different proportions.This paper systematically studied lead and zinc.The effect of different ratios of tailings sand on the basic working performance and radiation shielding performance of lead-zinc tailings sand radiation-proof concrete.The main research contents of the thesis are as follows:(1)The lead-zinc tailings sand concrete with six different lead-zinc tailings replacement rates was prepared by using the substitution ratio of lead-zinc tailings sand(0%,20%,40%,60%,80%,100 respectively).%),and compared with the performance of ordinary concrete,by measuring the slump,lead toxin leaching,cubic compressive strength and other test methods to comprehensive analysis of lead and zinc tailings performance.The test results show that when the lead and zinc tailings content is 40%~60%,the slump and strength of lead and zinc tailings meet the design requirements.When the lead and zinc tailings content exceeds 60%,the strength of concrete decreases obviously.After more than 80%,the decline is large.(2)Comparative analysis of the shielding ability of lead-zinc tailings sand concrete to?-rays under different plate thicknesses.It is found through analysis that with the increase of concrete thickness,the shielding ability of concrete to?-rays is enhanced,and the?-ray pulse passing through concrete is enhanced.The number gradually decreases,the thickness of the concrete and the attenuation multiplication coefficient show a certain correlation,and increase with the increase of the thickness,indicating that the shielding ability is related to the thickness of the material.The thicker the concrete material,the better the shielding performance.(3)Compared with ordinary concrete,the shielding performance of lead-zinc tailings sand concrete is obviously improved under the five different dosages of 20%,40%,60%,80%and 100%,and the linear attenuation coefficient is improved respectively.3.06%,6.74%,10.42%,11.65%,12.88%.The thickness of the semi-attenuating layer and the ten-fold attenuation layer are gradually thinned with the increase of the amount,and the thickness can be reduced by about 11%.In the same gamma source,the ordinary concrete needs 4.252 cm thick to attenuate the ray intensity to half of the original.Lead-zinc tailings sand concrete is only 3.767cm thick.(4)Prepare anti-radiation mortar with lead-zinc tailings.The lowest and highest linear attenuation coefficients of the specimens are 0.134and 0.161 respectively.The pulse number of?source is compared with the number of pulses after shielding through the mortar.Obviously,the linear attenuation coefficient also increases accordingly.(5)Using XCOM to simulate the mass attenuation coefficient u_m of1kgV~10GeV lead-zinc tailings concrete with different content,analyze the concrete shielding performance,and the results show that the mass attenuation coefficient of lead-zinc tailings sand concrete in low energy region is better than ordinary concrete.obvious. |
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