Myanmar Tungsten-Tin Ore: Distribution and Beneficiation

Myanmar is renowned for its rich mineral resources, particularly timah dan tungsten, which are critical commodities in the global market. The country’s unique geological formations host significant deposits of Tungsten-Tin ores, primarily located in regions such as Kachin State and Shan State. As the demand for these metals continues to soar due to their various applications in electronics, aerospace, and manufacturing, understanding the distribution and characteristics of these mines becomes increasingly vital. This article aims to explore the distribution of Tungsten-Tin deposits in Myanmar, the concentration processes and equipment utilized in mining operations, the technical challenges faced during extraction, and the economic implications of these resources for both local communities and the national economy.

Distribution of Tungsten-Tin Ores in Myanmar

Tungsten-tin ore is an important mineral resource in Myanmar. The Myanmar Tungsten-Tin ore belt is located in the Western Granite Province of Indochina. The belt extends 1,200 km east of Pyinmana through Tanintharyi, Kayin, Mon, Kayah, and Shan states and is more developed in the north. Most of the cassiterite comes from alluvial deposits, while tungsten is mostly developed in veins. The surrounding rocks are clastic sedimentary rocks of the Paleozoic Mergui, Taungnyo, and Mawchi formations.

 

 

Hundreds of Tungsten-Tin deposits (points) have been discovered in this belt, among which the Mawchi deposit is large in scale. The quartz veins with Tungsten-Tin ore are located near the contact zone between granite and limestone, and some quartz veins cut through batu kapur. Another important Tungsten-Tin mine is the Hemmyingyi (Dawei) deposit, where the thickest tungsten-bearing quartz veins can reach 1.5 m, producing cassiterite and wolframite. In addition, in the Myeik (Mergui) area, alluvial cassiterite mining areas can be seen everywhere. At present, the mining areas are mainly located in Yamon Kazat, Maliwun, and Theindaw. Among them, the cassiterite in the Theindaw area also develops diamond mineralization.

Tungsten-Tin deposits are concentrated at the junction of Pyinmana Town and the southern part of Shan Prefecture, including alluvial deposits and primary deposits. Recently, an alluvial cassiterite mine was also discovered at the junction of the northern part of Shan Prefecture and Yunnan Province in my country. It is the northernmost tin deposit known so far, indicating that north Myanmar is also a potential area for the discovery of tin mines. In addition, the Myanmar Tungsten-Tin belt is also an enriched mining area for elements such as REE (rare-earth elements, English: rare-earth element, REE), niobium, and tantalum.

 

Tungsten-Tin Ore Dressing Process And Equipment

The beneficiation process of Tungsten-Tin ore usually includes steps such as crushing, grinding, gravity separation, flotation, magnetic separation, and electrostatic separation. The specific process needs to be adjusted according to the properties of the ore (such as embedded particle size, mineral symbiosis, etc.). The following is an introduction to typical beneficiation processes and main equipment:

Process Overview
1. Crushing: large ore → small ore particles
2. Penggerindaan: small ore particles → suitable grinding particle size
3. Gravity separation: separation of heavy minerals (tin, tungsten) and waste rock
4. Flotation (if necessary): further purification of tin and tungsten minerals
5. Magnetic separation (if necessary): removal of non-valuable ores
6. Concentration and dehydration: obtain the final tin and tungsten concentrates

1. Crushing and Grinding

(1) Crushing

Tungsten-Tin ore usually has a coarse embedded particle size and needs to be crushed first to reduce the ore particle size for subsequent grinding and sorting.

• Penghancuran kasar: jaw crusher (PE series), gyratory crusher
• Medium crushing: penghancur kerucut (HP, HST series), impact crusher
• Fine crushing: high-pressure roller mill, vertical shaft impact crusher

(2) Grinding

The crushed ore enters the grinding stage to dissociate the minerals fully.

• Ball mill (MQY, MQG series): used for grinding to make the ore reach an appropriate particle size. Suitable for coarse grinding.
• Rod mill (MB series): reduces over-crushing and is suitable for tungsten ore.

 

2. Pre-selection (De-sludging And Classification)

Cassiterite and wolframite (wolframite) have high density and can be de-sludged by classification to remove fine mud and improve sorting efficiency.

• Spiral classifier (FG series): used for coarse-grained classification.
• Hydrocyclone (FX series): used for fine-grained classification and de-sludging.
• High-frequency vibrating screen (such as a linear screen): improves screening efficiency.

 

3. Gravity Separation (Core Process)

Gravity separation is the separation of tin and tungsten minerals and other impurity ores by using different densities. Cassiterite and wolframite have a high density (cassiterite ~7g/cm³, wolframite ~7.5g/cm³), and gravity separation is the main recovery method.

(1)Jig separator

Sawtooth wave jig (JT series): suitable for coarse-grained tin and tungsten ores.

(2)Shaking table

The meja goyang separates minerals of different densities through shaking and water flow.
6-S shaking table: classic equipment, suitable for fine-grained separation.

(3)Spiral chute

The parasut spiral uses the sedimentation principle to classify minerals, suitable for the sorting of larger particles.
Glass fiber reinforced plastic spiral chute: suitable for medium and fine-grained tin and tungsten ores, with low energy consumption.

(4)Centrifugal concentrator

The konsentrator sentrifugal separates heavy metal minerals and improves the concentration effect.
Nielsen centrifugal concentrator: efficiently recovers fine-grained cassiterite.

 

 

4. Flotation (Auxiliary Process)

Flotation can further purify tin and tungsten minerals, especially when the ore contains other interfering minerals. For fine-grained or complex Tungsten-Tin ores, flotation can be used to improve the recovery rate.

Peralatan:
Mesin flotasi (such as mechanical flotation machine or air flotation machine): Separate tin and tungsten from impurities by selectively floating the minerals.
Reagent addition system: Add flotation reagents (such as collectors, inhibitors, and foaming agents) to improve the flotation effect.

(1) Cassiterite flotation

Collectors: such as benzo hydroxamic acid, oleic acid.
Inhibitors: water glass, sodium hexametaphosphate (to inhibit gangue).
Peralatan: XCF/KYF flotation machine, JJF flotation machine.

(2) Wolframite flotation

Collectors: such as oxidized paraffin soap, benzyl arsenic acid.
Adjusters: sodium carbonate, oxalic acid (to adjust pH).
Peralatan: BF flotation machine, SF flotation machine.

 

5. Magnetic And Electrostatic Separation (Concentration Process)

(1) Magnetic separation

Magnetic separation is used to remove some non-valuable ores (e.g., iron-containing minerals) to improve the purity of tin and tungsten minerals. Pemisah magnetik use magnetic separation to remove non-magnetic materials and improve the quality of minerals.

• Weak magnetic separation (CTB series magnetic separator): removes magnetic minerals (e.g., magnetite).
• Strong magnetic separation (SLon high gradient magnetic separator): separates tungsten ore from cassiterite.

(2) Electrostatic separation

High-voltage electrostatic separator (e.g., YD series): used to separate cassiterite from scheelite.

 

Technical Difficulties & Breakthroughs in Tungsten-tin Dressing

Recovery of fine-grained cassiterite

The suspension cone concentrator (centrifugal force enhanced gravity separation) is used, and the recovery rate of -0.074mm particle size is increased to 68%.
The microbubble generator (bubble diameter 0.1-0.3mm) is introduced in the flotation stage, and the fine particle adsorption efficiency is increased by 22%.

Treatment of muddy ore

When the mud content of the original ore exceeds 25% in the rainy season, the two-stage cyclone desludging (Φ500mm+Φ250mm combination) is used, and the mud removal rate reaches 92%.

Environmental protection and compliance transformation
The anti-seepage standard of the tailings pond is upgraded to EU Level B, and a composite layer of HDPE membrane (1.5mm) + sodium-based bentonite blanket is used. The transformation cost of a single mining area is about 1.8 million US dollars.

 

Economic Benefit Evaluation

Concentrate Index: The concentrate grade is stable at 55%-60% (10-15 percentage points higher than single gravity separation), and the comprehensive recovery rate is 87%-92%.
Operating Cost: The comprehensive cost of processing 0.5% tin ore is about 120-150 US dollars/ton of concentrate, which is 18% lower than the traditional process.

Catatan: The process selection needs to be combined with the characteristics of the mining area (for example, the tungsten, tantalum, and niobium content of the ore in Kachin State needs to increase the magnetic separation section), environmental protection policies, and investment budget for comprehensive decision-making.

 

Kesimpulan

In conclusion, the Tungsten-Tin mining sector in Myanmar presents both substantial opportunities and formidable challenges. The strategic distribution of these resources underpins their importance in the global supply chain; however, the complexities of extraction and concentration demand innovative approaches to overcome existing technical difficulties. By addressing these challenges through technological advancements and sustainable practices, Myanmar can enhance the economic benefits derived from its mining industry. A comprehensive evaluation of the economic impact highlights the potential for growth and development, facilitating a brighter future for both the mining sector and the communities that depend on it. The journey towards efficiently harnessing these vital resources will undoubtedly shape the economic landscape of Myanmar in the years to come.