Flotation machine is an equipment to sort minerals from the slurry with the help of the buoyancy of air bubbles by taking advantage of the differences in the physical and chemical properties of the mineral surfaces. Its working principle is based on the different hydrophobicity and hydrophilicity of minerals, through the addition of specific agents, so that the target minerals attached to the bubbles and floated up to the surface of the slurry, so as to separate from other minerals. With the continuous development of industrial technology, flotation machine has been widely used in many industries, including but not limited to mining, chemical industry, environmental protection and other fields and the rationality of its equipment selection for production efficiency, product quality and economic benefits has a critical impact. This in-depth discussion of the flotation machine equipment selection process needs to be considered in a variety of factors, such as processing capacity, ore properties, process flow, energy consumption, etc., aims to provide a comprehensive and practical guidance for the relevant industries in the selection and application of flotation machine reference.
一.Application industries of flotation machine
1.Mining industry
1.1 Metal Ore Beneficiation
In the field of metal ore beneficiation, flotation machine is widely used. Take copper ore as an example, copper ore is often accompanied by a variety of other minerals, such as pyrite, sphalerite and so on. Through the flotation process, the use of suitable trapping agents and foaming agents, copper minerals can be selectively attached to the bubbles, so as to achieve separation from the vein minerals and other associated minerals. In lead-zinc ore beneficiation, the flotation machine can effectively separate lead minerals and zinc minerals. Due to the difference in the floatability of lead and zinc minerals, lead minerals can be floated out first and then zinc minerals can be recovered by adjusting the system of flotation chemicals and the operating parameters of the flotation machine, so as to realise the efficient recovery of the two metals. For gold ore dressing, the flotation machine can enrich the gold minerals from the vein minerals, improve the grade of gold, and provide high-quality raw materials for the subsequent smelting process.
1.2 Non-metallic Ore Beneficiation
Non-metallic ore dressing is also inseparable from the flotation machine. For example, in graphite ore beneficiation, graphite has good natural floatability, the use of flotation machine can be separated from graphite and vein minerals such as quartz, mica, etc., to obtain high purity graphite concentrate, widely used in batteries, refractories, lubricants and other industries. In phosphorus ore beneficiation, the flotation machine can remove the impurities in the phosphorus ore, improve the grade of phosphorus ore, and meet the industrial demand of phosphorus fertiliser production and so on.
2.Chemical industry
In the chemical industry, flotation machine is used to process some raw materials or intermediate products with special properties. For example, in the purification process of some chemical raw materials, if the raw materials contain impurities and impurities and target components in the surface properties of the difference, can be separated by flotation machine. In the production process of some chemical products, will produce a specific component of the waste residue or waste liquid, through the flotation machine can be valuable components for recycling, which reduces the production cost, but also reduces the pollution of the environment. For example, in some non-ferrous metal smelters produce wastewater, may contain a small amount of metal ions that have not been fully reacted, through the addition of suitable flotation chemicals, the use of flotation machine can be enriched recovery of these metal ions, to achieve the recycling of resources.
3.Environmental Protection Industry
3.1 Sewage treatment
In the field of sewage treatment, the flotation machine can be used to remove suspended solids, oil and grease and some floatable pollutants in sewage. For example, for oily wastewater, by adding emulsion-breaking agents and flotation chemicals to the wastewater, the oil droplets will coalesce and attach to the air bubbles, which will float to the water surface with the help of the flotation machine, thus realising the separation of oil and water. In municipal wastewater treatment plants, flotation machine can be used as a deep treatment unit to further remove the tiny particles and colloidal substances in secondary treatment effluent, and improve the effluent water quality, so as to achieve higher discharge standards or reuse standards.
3.2 Solid waste treatment
In solid waste treatment, the flotation machine can be used to recover metals and other valuable substances from the ash residue after waste incineration. Waste incineration ash usually contains a certain amount of metal, such as iron, copper, aluminium and so on, through the crushing, screening and other pre-treatment, the use of flotation machine can be separated from the ash, to achieve the recycling of resources, but also to reduce the harm of solid waste to the environment.
二.Flotation machine equipment selection
1.processing capacity
Processing capacity is the primary consideration in the selection of flotation machine. Different sizes of production enterprises have different requirements for the processing capacity of the flotation machine. In determining the processing capacity, it is necessary to consider the processing capacity of raw materials, production scale and production continuity and other factors. Generally speaking, large-scale mineral processing plants or industrial enterprises need to process a large number of raw materials, and should choose flotation machines with large processing capacity, such as large-scale mechanical agitation flotation machine or aerated flotation machine. Small enterprises or experimental research institutions, due to the small processing capacity, can choose a relatively small processing capacity of the flotation machine, such as the laboratory with a small flotation machine. The calculation of processing capacity is usually based on the nature of the ore, grade and concentrate grade and other parameters, through the corresponding formula for estimation, to ensure that the selected flotation machine can meet the actual needs of production.
2.Ore properties
2.1 Mineral composition
The mineral composition of the ore has an important impact on the selection of flotation machine. If the mineral species in the ore is complex, the symbiotic relationship is close, you need to choose the flotation machine with strong sorting capacity. For example, for polymetallic symbiotic ores, the mechanical stirring flotation machine can make the slurry and chemicals fully mixed through strong stirring, and promote the selective flotation of minerals. For ores with relatively simple mineral composition, relatively simple structure and low cost flotation machine can be used, such as some small inflatable flotation machine.
2.2 Particle size characteristics
The particle size of the ore directly affects the flotation effect and the selection of flotation machine. Generally speaking, coarse-grained minerals need larger bubbles and stronger stirring force to achieve effective flotation, so the mechanical stirring flotation machine with larger stirring intensity can be used. Fine-grained minerals are more suitable for flotation in an environment with uniform inflation and moderate stirring intensity, and the inflatable flotation machine has certain advantages in processing fine-grained minerals. For ores with a wide range of particle size, it may be necessary to use a combination of several types of flotation machine, such as coarse flotation machine to deal with the coarse part, and then fine flotation machine to deal with the fine part, in order to improve the overall flotation efficiency.
3.Process Flow
3.1 Complexity of flotation process
The complexity of the flotation process determines the configuration and selection of the flotation machine. Simple flotation process, such as a single mineral roughing, a selection process, can choose a simple structure, easy to operate flotation machine. For complex multi-stage flotation processes, such as those containing multiple roughing, multiple selection and sweeping, it is necessary to choose flotation machines with different performance characteristics for reasonable matching. For example, in the first stage of roughing, the flotation machine with large processing capacity and high mixing intensity can be selected to quickly enrich most of the target minerals; and in the subsequent selection stage, the flotation machine with high flotation precision and the ability to further improve the grade of the concentrate needs to be selected.
3.2 Matching with other equipment
Flotation machine needs to work with other equipment such as crusher, mill, classifier and so on in the process. Therefore, the matching of the flotation machine with these equipments should be fully considered in the selection. For example, the feed size of the flotation machine should be matched with the product size of the mill and classifier, and the processing capacity of the flotation machine should be compatible with the production capacity of the upstream equipment to ensure the smooth operation of the entire process.
4.Energy consumption
With the rising cost of energy, energy consumption has become a non-negligible factor in the selection of flotation machines. Different types of flotation machine energy consumption varies greatly. Mechanical stirring type flotation machine relies on mechanical stirrer to achieve pulp stirring and inflation, its energy consumption is relatively high; while inflatable flotation machine is mainly inflated to the pulp through external inflatable device, the stirring intensity is relatively low, and the energy consumption is also low. When selecting the type, the energy consumption of different flotation machines should be comprehensively evaluated according to the energy cost and production scale of the enterprise, and the equipment with lower energy consumption should be selected to reduce the production cost. At the same time, some new energy-saving flotation machines are emerging, such as the adoption of high-efficiency impeller design, optimisation of the filling system and other technical means to reduce the energy consumption of the flotation machine, which can be given priority in the selection.
Flotation machine in the mining industry, chemical industry, environmental protection and other industries have a wide range of applications, different industries have their own performance requirements for flotation machine. When selecting flotation machine equipment, it is necessary to comprehensively consider the processing capacity, ore properties, process flow, energy consumption and equipment maintenance and operating costs and many other factors. Only according to the actual production needs, a reasonable choice of flotation machine, in order to ensure the efficient and stable operation of the production process, to achieve the effective use of resources and maximize economic benefits. In the future, with the continuous progress of science and technology, the performance of the flotation machine will continue to improve, and the application areas will be further expanded to provide more powerful support for the sustainable development of various industries.
