Refining process for lepidolite in tantalum-niobium ore waste rocks

The invention relates to a refining process for lepidolite in tantalum-niobium ore waste rocks. A combined method with magnetic separation, high gradient magnetic separation, dense medium separation and flotation is adopted. The flotation adopts the process of rough flotation, dual fine flotations and sweeping. The process for refining the lepidolite from the granite-type tantalum-niobium ore waste rocks is provided. The tantalum-niobium ore waste rocks are crushed, screened, ground and subjected to high-frequency screening, spiral grading, permanent magnet magnetic separation for iron removal, high gradient magnetic separation, dense medium separation and flotation, so that lepidolite concentrates are obtained. By means of the method, the lepidolite concentrates are separated from the tantalum-niobium ore waste rocks. The lepidolite concentrates contain at least 4.5% of Li2O, at least 8.0% of K2O and Na2O and at most 0.10% of TiO2 and Fe2O3, the recovery rate of the lepidolite concentrates is larger than 80%, the qualities of the lepidolite concentrates meet the requirement of national standards, and the recovery rate of the lepidolite concentrates exceeds the industry level.