Angola | Mineral resource distribution and placer gold beneficiation technology
1. Basic national conditions and mining status Angola is located in the southwest of Africa, bordering the Republic of the Congo and the Democratic Republic of the Congo to the north, Zambia to the east, Namibia to the south, and the Atlantic Ocean to the west. It is one of the important seaports in central and southern Africa. As the largest oil producer in sub-Saharan Africa, its national economy is heavily dependent on the oil industry (accounting for 60% of the total economy). In recent years, the fluctuation of international oil prices has prompted Angola to accelerate the economic diversification strategy, focusing on the development of mineral resources such as diamonds, iron ore, copper ore, and gold mines.
II. Distribution of major mineral resources (key areas) (I) Pillar minerals Petroleum Core position: Oil and gas development accounts for 25.08% of GDP (2016), crude oil production is 1.73 million barrels/day International cooperation: Total, BP, Sinopec and other multinational companies lead the development Export market: China, the United States, India are the main.
Angola mineral distribution map
2. Diamond state-owned enterprises: Endiama (National Diamond Company), Sodiam (trading franchise) Largest mine: Catoca open-pit mine (multinational joint venture development) Reserve advantage: total reserves of about 1 billion carats, 50% of which are gem-grade Core production areas: kimberlite and alluvial deposits in Lunda Norte and Lunda Sul Main development: Output: 9.016 million carats in 2015.
Table of major mining development projects in Angola
II) Strategic metal minerals Iron ore Kassinga Iron Mine (Huila Province): reserves of 400 million tons, grade 50%-60%, historically annual production of 6.1 million tons Cerca Iron Mine (Kwanza Norte Province): Chinese capital participates in exploration, potential annual production of 2.76 million tons Core deposits: Infrastructure: A dedicated railway in the mining area connects the Namibe Port Copper Mine and the lead-zinc mine Loeto Lead-Zinc Mine (Kwanza Sul Province): zinc grade 2.2%, layered sedimentary sulfide ore Zenza Copper Mine (Luanda Province): sedimentary oxide ore, grade 2% Cachoeira do Binga Copper Mine: reserves of 140,000 tons, mineralization in the Early Cretaceous.
Angola Diamond Development Project List
Gold mines Kamoa-Kakula Gold Mine (North): One of the world's largest gold mines, with reserves of over 30 million ounces Chitozero Gold Mine (Central): Traditional main production area (III) Non-metallic and industrial minerals Phosphate mines Cacata Phosphate Mine (Minbos, Australia): Reserves of 5 million tons, P₂O₅ grade of 23%, planned annual production capacity of 800,000 tons Main distribution: Cabinda Province and Zaire Province Development progress: Building materials High-quality granite: Mainly red/black granite in Huíla Province and Namibe Province Rich in marble resources.
III. Challenges and opportunities in mining development War legacy: 27 years of civil war led to stagnation of geological work and low exploration level Economic transformation needs: The government urgently needs to reduce its dependence on oil through iron ore, phosphate, gold and other projects International cooperation opportunities: Chinese companies have participated in the development of iron ore and copper mines. Potential areas include: Reopening of Kazinga Iron Mine Large-scale mining of Kamoa-Kakula gold mines Construction of phosphate deep processing industry chain IV. Resource distribution diagram (abstract).
1. scrubber trommel(pretreatment) Gold ore usually contains a lot of impurities such as clay and gravel, and needs to be washed and screened first to separate the gold particles and grade them. Main equipment: Ore washing and screening machine Function: Break clay lumps, separate the wrapped gold particles Screening and grading (such as +10mm, -10mm+2mm, -2mm, etc.) Advantages: Reduce the load of subsequent equipment and improve the sorting efficiency Can be used with high-pressure water guns to improve the degree of dissociation
2. Roughing (recovering medium and coarse gold particles) (1) Jig machine (suitable for 0.5~10mm gold particles) Principle: Use pulsating water flow to separate minerals of different densities, and the gold particles settle to the bottom Applicable conditions: Process medium and coarse gold placer (>0.5mm) Can process higher grade ores, and the recovery rate can reach 80%~90% Advantages: Large processing capacity, suitable for roughing Can operate continuously, high degree of automation.
(2) carpet sluice box (applicable to gold particles of 0.1~2mm) Principle: The ore pulp flows through the inclined chute with grid pattern. The gold particles are deposited on the bottom of the chute due to their large specific gravity. Applicable conditions: Applicable to the recovery of fine gold particles (0.1~2mm) Commonly used for the initial enrichment of placer gold mines Advantages: Simple structure, low investment Can recover fine gold, but manual cleaning of concentrate is required 3. Fine gold recovery (centrifuge) Centrifugal concentrator (applicable to gold particles of 0.02~0.5mm) Principle: Use centrifugal force to strengthen gravity separation to enrich fine gold Applicable conditions: Applicable to fine gold particles (<0.5mm) Can recover fine gold that is difficult to capture with traditional chutes Advantages: High recovery rate (up to more than 90%) Applicable to low-grade placer gold mines
4. Concentration (improving the grade of gold concentrate) Shaking table (applicable to 0.02~2mm gold particles) Principle: Use the horizontal water flow and vertical vibration of the bed surface to stratify the minerals according to their specific gravity Applicable conditions: Used for purification of rough concentrates in jigs and centrifuges Can produce high-grade gold concentrates (>90% recovery rate) Advantages: High sorting accuracy, can separate gold and impurities Applicable to small and medium-sized concentrators
