Preparation method of coal gangue ceramsite for adsorbing Cr(VI)

Abstract

The invention discloses a preparation method of coal gangue ceramsite for adsorbing Cr(VI). The preparation method comprises coal gangue raw materials, slaked lime, coal gangue clinker and carbon powder. The preparation method specifically comprises the steps that the raw materials are stirred and mixed, then the rotating speed is adjusted, after the powder material basically disappears and granulation is completed, the mixture is placed in an electric heating air blowing drying oven to be dried, calcined, subjected to heat preservation, cooled and sieved, and the ceramsite for adsorbing Cr(VI) is prepared. The coal gangue raw material used in the method belongs to solid waste, is rich in reserves and wide in source, and the slaked lime and the carbon powder are cheap and easy to obtain. The method has the advantages that waste treatment is well realized by using waste, and the application prospect of the coal gangue is expanded.

Description

technical field [0001] The invention relates to a method for preparing coal gangue ceramsite used for Cr(VI) adsorption, in particular to a method for preparing adsorbed ceramsite used for heavy metal wastewater treatment. Background technique [0002] In recent years, with the large-scale advancement of industrialization, the problem of discharging heavy metal Cr(VI) ion wastewater into the environment has become more and more serious. Because Cr(VI) is extremely toxic and cannot be degraded naturally, it can only migrate and transform, which will Oral, respiratory or skin contact absorption, studies have proved that its compounds have obvious carcinogenic effects, and may also induce gene mutations, causing great damage to the natural environment and human health; there are many methods for treating heavy metal ion wastewater, mainly including There are three aspects: physical method, chemical method and biological method. Among them, adsorption method, as one of the physi...

AI Technical Summary

Problems solved by technology

[0003] Coal gangue, also known as kaolinite coal gangue, is an associated mineral in coal-measure strata. With the massive development of coal, more and more coal gangue is discarded as an accompanying organism. It is understood that the annual emission of coal gangue in my country is It is between 300 million and 350 million tons, and the cumulative stacking volume is about 5 billion tons. It is the solid waste with the largest output and cumulative accumulation of industrial solid waste in China, but its utilization rate has been less than 40% for many years. , can only occupy a large amount of land, such as farmland, slopes, ravines, etc. for stacking. In the long run, on the one hand, it will occupy a large amount of land resources, and on the other hand, it will cause environmental pollution

[0004] In recent years, the research on using coal gangue modification as an adsorbent to treat printing and dyeing or heavy metal ion wastewater has gradually increased. Most researchers focus on powdery kaolin, through acid leaching, alkali leaching, adding additives or organic treatment, coated The method realizes the modification of kaolin, and then directly uses powdered kaolin as an adsorbent. Although the adsorption effect has been greatly improved compared with that before modification, the modification conditions are complicated, and the raw materials such as many drugs used in the modification process are expensive. , and many additives themselves have potential hazards to the environment and human health, and it is difficult to achieve large-scale treatment of wastewater. At the same time, it is difficult for modifiers to dissociate and enrich printing and dyeing or heavy metals after the reaction is completed, and thus cannot make these The adsorbate is effectively used again, and the adsorbent itself cannot be recycled, resulting in a lot of waste

[0005] The adsorbent prepared by Chen Lirong et al. has an adsorption capacity of 9.12 mg / g for Cr(Ⅵ). The cost of aluminum chloride added to the raw material is high, and the powdered adsorbent cannot be recycled (Chen Lirong, Wang Siqi, Jiang Qinghong, etc. Modified coal gangue Preparation and Characterization of Composite Adsorbent and Study on Adsorption and Removal of Cr(Ⅵ)[J]. Silicate Bulletin, 2016, 35(05): 1450-1458.); Adsorption capacity of adsorbent prepared by Zhang Yongli et al. It is 9.14 mg / g, but the preparation process relies on acid leaching, the process is complicated, the cost is high, and it cannot be recovered (Zhang Yongli, Zhu Jia, Shi Chuan, et al. Modification of kaolin and its adsorption characteristics for Cr(Ⅵ)[J]. Environmental Science Research, 2013, 26(05): 561-568.); The adsorbent prepared by Li Huiyun et al. has an adsorption capacity of 0.81 mg / g for Cr(Ⅵ), which has low adsorption capacity and low utilization value (Li Huiyun, Guo Jinfu. The influence of heat treatment temperature on the structure of coal gangue and the adsorption performance of Cr~(6+)[J]. The amount is 4.73 mg / g, the adsorption capacity is low, and the cost of chitosan used in raw materials is very high (Yang Wenyi, Xie Hualin. Chitosan intercalated kaolin for adsorption of heavy metal ions in electroplating wastewater[J]. Material Protection, 2016, 49 (11):75-78+8.)