The invention discloses a method for comprehensively extracting
lithium from
lepidolite and recovering by-products, and relates to the technical field of comprehensive utilization of
lepidolite resources, and the method comprises the following steps: step 1, burdening and conversion
roasting; secondly, water leaching and
fluorite flotation are conducted; 3, acidizing
roasting and secondary leaching, wherein
sulfuric acid with the concentration larger than or equal to 98 wt% is added into
tailings obtained in the step 2 for acidizing
roasting; carrying out secondary leaching on an acidified roasting product by using the filtrate obtained in the step 2; step 4, performing
slag-liquid separation and preparing a
lithium product; and 5, preparing
potassium sulfate and
mirabilite. According to the invention, limestone ore blending conversion roasting
fluorine fixation is carried out, so that the generation of a large amount of
hydrogen fluoride is avoided from the source,
fluorine is converted into a high-value product instead of a
pollutant through
fluorite flotation,
lithium precipitation carbon sources are all from primary roasting limestone and
fuel gas containing carbon, and final waste residues leached after acidification roasting are used as qualified
cement raw materials; and
zero emission of
solid waste is realized, and the environment-friendly
bottleneck of the industry of extracting lithium from
lepidolite is thoroughly solved.