，要求为学术研究论文
Recovery of Tungsten from Tungsten Ore and Its Application
Abstract
This study aims to examine the recovery and utilization of tungsten from tungsten ore by physical and chemical methods. Tungsten is an important mineral resource and is mainly used in steel alloys, medical-grade hard alloys and for cutting tools. Several methods of recovering tungsten from tungsten ore are studied, including gravity separation, heavy-medium separation, flotation, high-intensity magnetic separation, chemical leaching, etc. The advantages and disadvantages of each method are also discussed. Furthermore, the applications of recovery tungsten are introduced in detail.
Keywords: Tungsten, Recovery, Application
1 Introduction
Tungsten, commonly knownas wolframite, is a heavy metal mineral resource. It is internationally recognized as a strategic mineral resource and is a critical raw material for high-tech industries and defense-related industries [1]. The demand for tungsten has grown rapidly over the past decades mainly due to its application in the steel industry, hard alloy and cutting tools [2]. Tungsten is usually mined from two main types of ore, namely tungstenite (CaWO4) and wolframite (FeWO4 + MnWO4). Extracting tungsten from tungsten ore requires a series of physical and chemical processing techniques, including gravity separation, heavy-medium separation, flotation, high-intensity magnetic separation and chemical leaching [3].
2 Recovery of Tungsten from Tungsten Ore
2.1 Gravity Separation
Gravity separation is an effective and economical method for concentrating tungsten ore. It relies on the difference in specific gravity between tungsten and its gangue minerals. The processes can generally be divided into two categories, depending on the gangue minerals present in the ore. If the ore contains mainly quartz, then it is necessary to use a spiral concentrator to separate the heavy minerals from the gangue. If the ore contains low clay content and mainly scheelite, then a jigging machine is the best choice [4].
2.2 Heavy-Medium Separation
Heavy-medium separation has become popular for recovering tungsten. This type of process utilizes the difference in the specific gravity between tungsten and its gangue minerals to separate them. This process mainly consists of three stages, namely pre-concentration, selection and scavenging. Pre-concentration is carried out by creating a heavy medium containing a mixture of specific gravity media such as magnetite and ferrosilicon. The selection stage uses this heavy medium to separate the tungsten ore from gangue minerals. The scavenging stage is used to increase the tungsten recovery rate by removing particles which have escaped the previous stages [5].
2.3 Flotation
Flotation can be used to recover tungsten by using oxidizing agents such as oxygen and nitric acid to create an amenable condition for the selective flotation of scheelite and other minerals. The main advantage of this method is that it can be applied to a wide range of ore types and can achieve high tungsten recoveries. The disadvantage of this process is the production of a small amount of tailings which leads to resource waste and potential environmental pollution [6].
2.4 High-Intensity Magnetic Separation
High-intensity magnetic separation (HIMS) is increasingly being used to recover tungsten from tungsten ore. This method is based on the fact that tungsten has a higher magnetic susceptibility than the other minerals in the ore. This method uses a large electromagnet to form a magnetic field which can separate the tungsten ore from the gangue minerals. The advantages of this process are its simplicity, low cost and environmental friendliness. The disadvantage is that the process is not effective for ore containing low magnetic susceptibility particles [7].
2.5 Chemical Leaching
Chemical leaching is a process used to extract tungsten from tungsten ore by using acids or other reagents. This process is relatively simple and can achieve high tungsten recoveries. The main limitation of this process is that it produces a large amount of acid waste, which can pollute the environment if left untreated [8].
3 Applications of Recovered Tungsten
Recovered tungsten has a wide range of applications in various industries, including steel alloys, medical-grade hard alloys and cutting tools.
3.1 Steel Alloys
Tungsten is used as an alloying agent in steel production to increase the strength and wear resistance of the steel products. Tungsten is added to steel to form tungsten-steel alloys which are used to make tools with high hardness.
3.2 Medical-grade Hard Alloys
Recovered tungsten is used to produce medical-grade hard alloys which are used in various medical applications, such as dental prosthetics, orthopedic implants and ophthalmic instruments.
3.3 Cutting Tools
Recovered tungsten is used to produce cutting tools such as taps, drills and milling cutters. These cutting tools are used to cut and shape metal objects.
4 Conclusion
This study examined the recovery and utilization of tungsten from tungsten ore by physical and chemical processes. Five different methods were discussed, including gravity separation, heavy-medium separation, flotation, high-intensity magnetic separation and chemical leaching. The advantages and disadvantages of each method were described in detail. Furthermore, the applications of recovered tungsten in various industries such as steel alloys, medical-grade hard alloys and cutting tools were also introduced.
