Ore dressing process for medium-grade and low-grade mixed collophanite

An ore dressing process for a medium-grade and low-grade mixed collophanite, comprising the following steps:

• S1:
• crushing green ores to obtain crushed ores, wherein a particle size of the crushed ores is less than or equal to 60 mm;
• S2:
• screening the crushed ores to obtain fine-fraction ores and coarse-fraction ores divided into at least two size fractions, wherein a particle size of the fine-fraction ores is less than or equal to 8 mm, and a particle size of the coarse-fraction ores is more than 8 mm;
• S3:
• respectively performing a photoelectric separation to the coarse-fraction ores of different size fractions to obtain photoelectric separation concentrates and photoelectric separation tailings of each size fraction;
• S4:
• combining the photoelectric separation concentrates of the each size fraction to obtain pre- enriched concentrates;
• S5:
• combining the fine-fraction ores and the pre-enriched concentrates, and then performing an ore grinding to obtain minerals to be separated;
• S6:
• adding water to the minerals to be separated to obtain a floatation pulp, and then performing a floatation to obtain phosphate concentrates and tailings;
• wherein
• in step S6, the floatation comprises at least one time of roughing, at least one time of concentration and at least one time of scavenging, and further comprises the following steps:
• Al:
• adding an inhibitor and a collector into the floatation pulp, and performing stirring and aeration to obtain roughing concentrates and roughing tailings;
• A2:
• adding the inhibitor and the collector into the roughing concentrates, and performing stirring and aeration to obtain final phosphate concentrates and concentration middlings;
• A3:
• adding the inhibitor and the collector into the roughing tailings, and performing stirring and aeration to obtain scavenging concentrates and final tailings;
• and wherein
• the inhibitor is a mixed acid;
• the inhibitor comprises 4-6 parts of sodium tripolyphosphate, 2-3 parts of hexametaphosphate and 2-3 parts of phosphoric acid by weight;
• and
• the collector comprises 4-5 parts of sodium vegetable oleate and 1 part of dodecyl phosphate by weight.