Study On Occurrence And Release Characteristics Of Arsenic Gannan A Tungsten Mine Tailings And Soil

Gannan is the birthplace of Chinese tungsten industry, and is famous as “tungstenworld”.There are four tungsten ores after decades of exploitation, brings in the social economicdevelopment to our country, but at the same time, there are also impact on the local naturalenvironment and human survival health. Arsenic is one of the major heavy metal elements causedby mine environment pollution, arsenic in the mine tailings can through the pore of infiltrationand surface runoff into the soil, and these arsenic after a series of migration and transformationcan be absorbed by organisms, and eventually harm to human health.The paper through analyze the arsenic from mine tailings produced by tungsten ore ofGannan and the surrounding soil to mining area in full amount by silver diethyl dithiocarbamatespectrophotometry method, to understand the basic physical and chemical properties of soilaround mining area and enrichment characteristics of the arsenic.Results of the research showedthat the soil around mining area are skew acidic; In addition, the content of arsenic in tailings andsurrounding soil are significantly higher than that in the background level and in the soil Aswhere the nearer the tail ore deposits concentration is more obvious.The test research the feature of arsenic release in the soil and it’s main factors through thestatic release experiments. Results of the research showed that the oscillation sample processing,elevate of the system temperature and rise of soil pH will increase the release quantity of arsenic,the release and migration ability of arsenic in acidic conditions is less than in alkaline conditions,and release quantity will gradually increase with rising pH, when the pH reaches10to11, it is themaximum.Different forms of arsenic in varying degrees of harm to the environment. Test using Tessiersequential extraction analysed the arsenic in mine tailings and surrounding soil. Studies show that,In tailings, the arsenic mainly exists as the status of residual, and the proportion accounted for39.4%of the total arsenic; however, it mainly exists as the compound linked to oxides of Fe-Mn,its ratio is36.13%~38.63%of total arsenic.In the five status of arsenic, the release andmigration ability of residual arsenic is weakest, In tailings, the strongest of release ability statusare exchange and oxides of Fe-Mn, and the release amount reached78%and82.4%respectively in their forms. And in the soil,because of the content of Fe-Mn oxides is most, andthe average of percentage for emission is46.94%, so it dominate in the release and migrationprocess of arsenic.