Some new pre-selection methods for lead and zinc

Now, it may be used as a pre-selection in addition to re-election (heavy media sorting and jigging), as well as a variety of radiation methods with high selectivity and adaptability.
Radiation is the separation of minerals by means of chemical elemental spectroscopy or transmitted ray. The ore is divided into different products according to certain chemical elements (not related to what kind of minerals are present). This property of the radiation method is of great significance in the case of processing minerals with different (physical, chemical and physicochemical properties) minerals in the ore.
Foreign development and application of radiation beneficiation of great importance, for sorting non-ferrous metal ores, the most promising is based on the measurement of heavy minerals and rocks reflectance, fluorescence, conductivity, magnetic and fluorescent radiation Several kinds of beneficiation methods, such as radiation sorting method, photometric sorting method, fluorescent sorting method, γ-ray absorption sorting method, x-ray absorption sorting method, radiation resonance sorting method and infrared sorting method.
Wherein, [gamma] is a method of dressing a preselected fluorescence promising method, BAⅡлеев other had six different mining ore: cassiterite, tin, tungsten ores, tungsten ores, copper-nickel ore, cobalt ore, zinc ores of lead The samples were tested to prove that many non-ferrous metal ores can be sorted by gamma-radiation. Sorting a calcium hectorite iron - Results skarn sulfide lead-zinc ore in the following table.

Note: Particle size -75+50 mm

The Pynasalmi mine in Outokumpu, Finland, conducted an industrial test of the Gaya pre-selection machine with a capacity of 7 to 40 tons per hour. The measuring device comprises two radiation sources, a detector of sodium iodide, and pulse processing electronics a microprocessor data processing systems, and control the separation operation, the compressed air nozzle to separate waste rock and ore blocks.
The gamma measurement method is most suitable for measuring chromium , iron, nickel, copper, zinc, tin and lead, as well as mixtures of the above metals.
For heterogeneous ores, the average metal content should be between 0.4 and 0.5%. This method is feasible.
The test shows that when the galena pre-selection method is used to treat copper-zinc ore, 45% of waste rock can be discarded. The content of copper and zinc in waste rock is 0.17% and 0.14%, respectively. The recovery of copper and zinc in products is 82.9% and 95.5%. . When treating copper-zinc-cobalt ore, 24% of waste rock can be removed. The contents of copper, zinc and cobalt in waste rock are 0.18%, 0.08% and 0.02%, respectively. The recovery rate in the product is 97.8%, 98.6%. , 97%. When treating chrome ore, 40.2% of waste rock containing Cr ₂ O ₃ 7.4% can be removed, and the recovery rate in the product is 87.5%.
In addition, laser photoelectric sorting is also applied industrially.
The laser photoelectric sorter is based on the different light reflection characteristics of the constituent minerals in the ore. The 16-type laser photoelectric sorting machine is one of the newly developed general-purpose mechanical sorting equipments , and it is a major development of mineral processing equipment in the past ten years. Production practices have shown that this photoelectric sorter is a versatile one. Significant economic benefits and high processing capacity are promising sorting equipment. It is expected that this laser photoelectric sorting machine will have a tendency to replace pre-selected ore by hand selection and heavy medium sorting.
The black pine mine in Philipsburg, Montana, USA, was installed and established in July 1978. It was put into operation in January 1979 and processed 500 tons of raw ore daily. Selected ore containing mainly pyrite, chalcopyrite, galena, sphalerite, tetrahedrite, gray silver ore, manganese ore magenta silver and tungsten. The metal mineral is present in a layered or massive form in the quartz gangue.
Photoelectric beneficiation technology is mainly based on the following principles:
The number of photons obtained from the surface of the rock exposed to light is proportional to the intensity of the light; the color varies with the non-uniformity of the reflectance caused by the different wavelengths of the spectrum. The laser source and the rotating barrel are used for illumination, and the reflectance data is collected by a photomultiplier tube. The reflectance data was collected and analyzed by an electronic processor, and the ore valve was used to mechanically separate the ore and waste rock.
1
The ore is crushed to 4′′ by a jaw crusher , and is divided into two grades of +—~-2′′ and +2～-4′′ by double-layer vibrating screen, which are stored in light 2 respectively.
Electric dressing feedstock bin. Before the sorting operation, the photoelectric concentrator is adjusted to adapt to the feeding of different size grades, and the materials are washed and then fed into the photoelectric concentrator. Qualified products and waste rock are transported outside the factory by belt.
After several months of production practice, the black pine mine photoelectric concentrating plant shows that the electroporation has the following advantages:
(1) The average yield of qualified products and waste rock was 68% and 32%, respectively.
(2) The average silver content of qualified products increased to 38%, the total recovery rate reached 93%; the copper recovery rate increased to 46%, and the total recovery rate was 95%.
(3) Equipment utilization is close to 85%.
(4) 50 tons of mixed material per hour, the average air consumption is 900 cubic feet per minute.

The machine is used for cutting long tubes for scaffold vertical pole, after cutting the pipe ends with a smooth blade, without burr, which reduces manual grinding. It can load and unload the tube automatically, so it reduces work intensity.