Flotation process of low-grade monazite in ilmenite

The invention provides a flotation process of low-grade monazite in ilmenite, which comprises the following steps: roughing flotation of ilmenite: adding sodium dodecyl sulfate into raw ore, mixing and stirring, adding water glass, copper sulfate, a collecting agent, terpenic oil and sodium carbonate, and adjusting the pH value to 9.0-9.5 by sodium carbonate to obtain qualified ilmenite and tailings; the tailings are selected and floated, water glass, copper sulfate, a collecting agent and terpenic oil are added again, and the collecting agent is formed by mixing fatty acid methyl ester, methyl alcohol and soybean oil. According to the method, a fine flotation process is added after roughing flotation, and the collecting agent is combined with microwave pre-activation pretreatment, so that the phosphorus content of monazite is increased while the phosphorus content of ilmenite is reduced. According to the flotation process and the formula of the collecting agent, the ilmenite yield is higher than 97%, the TiO