There are about 20 types of mercury minerals in nature. The industrially significant mercury minerals are mainly cinnabar, followed by natural mercury, metacinnabar, and livingstoneite. The industrial types of mercury ore include single mercury ore, mercury antimony ore, mercury uranium molybdenum ore, mercury lead zinc ore, mercury copper ore, mercury gold ore, mercury polymetallic ore, and the like. Important mercury-producing countries in the world include Spain, Italy, China, Yugoslavia, Canada, the United States, Mexico, Algeria, and Turkey.
The earliest direct smelting of a single mercury sulfide ore. Cinnabar has high density, low hardness, brittleness, and good floatability. When designing the beneficiation process, it is necessary to prevent cinnabar from being over crushed during the crushing and grinding process.
The mercury ore beneficiation process includes pre-selection, gravity separation, flotation process, and gravity-flotation combined processes. Hand-picking is the traditional pre-selection method of mercury ore. Manual hand-picking can get concentrate and throw away some waste rock. When the ore particle size is 20 ~ 100mm, the throwing rate of waste rock can reach 40% ~ 80%. The waste stone can also be removed with a sieving machine, such a vibrating screen.
Mercury flotation is an effective method to recover fine-grained embedded mercury minerals and polymetallic symbiotic ore. Usually one-stage or two-stage grinding, multiple concentrating and scavenging flotation processes. The activator of cinnabar flotation is copper sulfate and lead acetate, and the collectors are xanthate, aerofloat, and so on.
When the ore contains Hg 0.1% to 0.5%, the mercury concentrate grade is 10% to 30%, and the recovery rate is 90% to 96%. The combined gravity-flotation process is widely used in mercury ore beneficiation. The high-grade cinnabar concentrate is selected by mining jigs or shaking tables, and the tailings are re-ground and floated to obtain concentrates.