The exhaust gas emissions from the company's production process are mainly boiler exhaust gas and tail gas from drying in the lithium salt sector. Online monitoring facilities are installed at the main discharge ports and all indicators meet national environmental requirements.
Particulate matter, sulphur dioxide, and nitrogen oxide emissions per unit of product (equal to 10,000 tonnes of LCE) were lowered by 1.77 tonnes, 2.75 tonnes, and 10.64 tonnes, respectively, in 2021.
Desulphurisation and denitrification to reduce coal-fired boiler emissions
In 2019, the company carried out desulphurisation and denitrification of the 50-ton boiler at the Mahong Plant by installing new desulphurisation tower components, fly ash circulation devices, flue gas recirculation devices and SNCR (ammonia spraying) devices. After the transformation, the emission concentrations of sulphur dioxide and nitrogen oxide has stabilised below 100 mg/Nm³. After the desulphurisation of the acidification kiln, there is basically no acid mist discharged from the outlet of the electric demister chimney; the sulphur dioxide content is less than 50 mg/Nm³; the sulphuric acid mist content at the outlet is 20-50 mg/Nm³. Owing to the advanced and environmentfriendly equipment, the emission reduction effect was significant, winning the 2019 Air Pollution Prevention Special prize that was issued by the central government.
Acidification kiln water-gas-to-natural-gas conversion project costed about RMB 500,000 in total, and was put into use in March 2021. According to data, it can save nearly RMB 420,000 of operating costs every year, reduce the impact on production from 15 days per year to 0 days and the average β-lithium oxide content of acid clinker from 0.11% to 0.074%, and increase the overall yield by about 0.5 %. After the conversion to natural gas, there is no long the problem of tar treatment and the exhaust gas can be directly emitted without desulfurization and denitrification, which reduces the operating cost of the environmental protection system.
