技術分野： The present invention relates to a beneficiation method, in particular to a beryl ore beneficiation method.

背景アート： Beryl is a silicate mineral, mostly produced in pegmatite deposits, and is mainly used for producing the rare metal beryllium and its compounds. Beryllium and its compounds are important raw materials for many sectors of the national economy. For example, beryllium‑copper alloys have the advantages of high hardness, high strength and good thermal conductivity, and are important materials for the electronics, electrical and automotive industries; beryllium oxide has good thermal conductivity and low electrical conductivity, making it suitable for radiators and electrical insulators used in the manufacture of microprocessors, radar and transistor devices; metallic beryllium has the advantages of high melting point, low density, high specific strength, resistance to oxidation at room temperature, low expansion coefficient, good dimensional stability, etc., and is widely used as structural material in the aerospace industry, as shielding material in nuclear reactors, and for preparing neutron sources, thus it has become an important “space metal”. Existing beryl beneficiation methods are mostly acid or alkali processes, and mostly use strong acids or strong alkalis for separation, and even require heating, water washing, and dewatering during the beneficiation process, as well as pre‑removal of magnetic minerals and easily floatable minerals. These methods not only have complex processes, long process flowsheets, large equipment investment, high energy consumption, and low economic benefits; moreover, strong acids or strong alkalis cause significant corrosion to equipment, directly affecting the service life of the equipment and increasing operating costs. More seriously, strong acids or strong alkalis also cause great environmental pollution. In addition, in today’s society where mineral resources are increasingly scarce, how to fully and effectively utilize low‑grade lean ores or tailings is also an important subject of research. Therefore, it is necessary to improve the existing technology to meet the requirements of industrial production and ecological environment.

発明の概要： The object of the present invention is to overcome the deficiencies of the prior art and to provide a method that has a simple process, short flowsheet, no environmental pollution, low operating costs, high yield, and can produce beryllium concentrate from lean ores or tailings.

The present invention achieves the above object through the following technical solutions: it includes gravity concentration of tailings or lean ores and fluorite flotation, characterized in that the following components are added to the ore:

Sodium carbonate 300‑800 g/t, collector 400‑1300 g/t,

sodium silicate 200–1200 g/t, sodium hydroxide 50–300 g/t, aluminum sulfate 250–1000 g/t, iron salt 100–600 g/t, frother 10–30 g/t, and cationic collector 50–200 g/t. After fluorite flotation, beryl reverse flotation is carried out to obtain a beryllium oxide concentrate.

The specific process steps of the present invention are as follows:

1. Gravity concentration of the tailings is performed using conventional techniques, yielding a tungsten concentrate;
2. To the remaining tailings, the following components are added for fluorite flotation:
   • Sodium carbonate: 300–800 g/t,
   • Sodium silicate: 200–1200 g/t,
   • Aluminum sulfate: 250–1000 g/t,
   • Collector: 300–1000 g/t,
   • The pH is adjusted to 7.5–9.5. The separated impurities are then processed by conventional techniques to recover a fluorite concentrate;
3. To the remaining tailings, the following components are added for fluorite scavenging:
   • Collector: 100–300 g/t,
   • Frother: 20–30 g/t,
     The separated impurities are sent to the fluorite flotation circuit to recover fluorite concentrate;
4. To the remaining tailings, the following components are added for beryl roughing (beryl reverse flotation):
   • Sodium hydroxide: 50–300 g/t,
   • Iron salt: 100–600 g/t,
   • Cationic collector: 50–200 g/t,
   • Frother: 10–20 g/t,
   • The pH is adjusted to 7.5–9. After one stage of scavenging of the separated impurities, the froth impurities are discarded as tailings, and the scavenger concentrate is returned to the beryl roughing stage;
5. To the remaining tailings, the following components are added for beryl cleaning (beryl reverse flotation):
   • Cationic collector: 20–60 g/t,
   • Frother: 5–10 g/t,
     A beryllium oxide concentrate is obtained, and the cleaning tailings are returned to the beryl roughing stage.

In the process method of the present invention, the collector is oxidized paraffin soap or oleic acid. The frother is pine oil. The iron salt is ferric chloride, ferric sulfate, or ferrous sulfate. The cationic collector is a primary amine, secondary amine, or ether diamine having 10–18 carbon atoms.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. It does not require dewatering, heating, ore washing, nor removal of magnetic minerals and easily floatable minerals. A beryllium oxide concentrate with relatively high grade can be obtained by only one stage of roughing, one stage of cleaning, and one stage of scavenging. The process is simple, the flowsheet is short, and equipment investment is low.
2. The entire process only requires the addition of small amounts of alkali, salts, collectors, and frothers to obtain the beryllium oxide concentrate in a single pass. The weakly alkaline reagents do not corrode equipment. The discharged wastewater after treatment far exceeds national standards, and no toxic or harmful gases are generated during production, thus causing no environmental pollution.
3. A single production line can simultaneously produce tungsten, beryllium, and fluorite concentrates, with high equipment utilization, high product grades, and an overall recovery of 60–80%, resulting in considerable economic benefits.

Therefore, the present invention provides a new breakthrough in the flotation of beryl from pegmatite deposits, fundamentally solving many problems in the practical production and application of such deposits, and allowing full and effective utilization of valuable mineral resources.

Figure 1 is the process flowsheet of the present invention.

The present invention is further described below with reference to embodiments.

例 1

The discarded tailings from the Hutiaoxia Tungsten Mine in Zhongdian County, Yunnan Province, China, were selected as raw material. The chemical composition of the tailings was: WO₃ > 0.73%, BeO > 1.3%, CaF₂ > 42.4%, Al₂O₃ 2.4%, CaO 4.6%, gangue containing quartz 43.42%, mica 2%, calcite 8.2%, organic matter 3.5%, pyrite 15%, and trace amounts of other minerals. The specific process steps were:

1. Gravity concentration of the tailings was performed using conventional techniques, yielding a tungsten concentrate.
2. To the remaining tailings, the following components were added for fluorite flotation:
   • Sodium carbonate: 400 g/t,
   • Sodium silicate: 500 g/t,
   • Aluminum sulfate: 300 g/t,
   • Oxidized paraffin soap: 600 g/t,
     The pH was adjusted to 7.5–9.5. The separated impurities were then processed by conventional techniques to recover a fluorite concentrate.
3. To the remaining tailings, the following components were added for fluorite scavenging:
   • Oxidized paraffin soap: 200 g/t,
   • Pine oil: 30 g/t,
     The separated impurities were sent to the fluorite flotation circuit to recover fluorite concentrate.
4. To the remaining tailings, the following components were added for beryl roughing (beryl reverse flotation):
   • Sodium hydroxide: 100 g/t,
   • Ferric chloride: 500 g/t,
   • Octadecyl amine: 160 g/t,
   • Pine oil: 20 g/t,
     The pH was adjusted to 7.5–9. After one stage of scavenging of the separated impurities, the froth impurities were discarded as tailings, and the scavenger concentrate was returned to the beryl roughing stage.
5. To the remaining tailings, the following components were added for beryl cleaning (beryl reverse flotation):
   • Octadecyl amine: 60 g/t,
   • Pine oil: 10 g/t,
     A beryllium oxide concentrate was obtained, and the cleaning tailings were returned to the beryl roughing stage.

The octadecyl amine used in steps 4 and 5 was a primary amine containing 18 carbon atoms.

The grades and recoveries of the obtained beryllium oxide concentrate, tungsten concentrate, and fluorite concentrate were as follows:

The following table shows the reagent dosages for each step in Examples 2, 3, and 4. The process steps and methods were the same as in Example 1. Example 2 represents the reagent dosages used in a scale‑up test, in which a total of 500 tonnes of tungsten tailings were processed, yielding the following indices:

Reagent dosages for Examples 2, 3, and 4 (g/t):