Investigation of tin-tantalum-niobium deposits mining in Nigeria

Barakindawa granite weathering crust type Tin, tantalum, niobium, deposit mining in Nigeria.

Nigeria is located in the southwestern part of the African continent. The terrain is high in the north and low in the south. The tectonic structure is between the West African platform and the Congo platform. The Jos Plateau is located in central Nigeria, and the northern part of the plateau is located in the western part of the state of Bauchi. The Joss Plateau is a lava plateau, and the plutons in the northern and eastern part of the plateau are mainly Precambrian granular and porphyritic biotite granite, Mesozoic Jurassic granite, quartz porphyry, syenite, and diorite. Among them, the Precambrian coarse-grained porphyritic biotite granites are the most widely distributed. The Jurassic granular biotite granite and sporadic outcropping quartz porphyry, syenite and diorite bodies emplaced and cut the Precambrian biotite granite basement.

Most of the exposed strata in the area are Mesozoic Jurassic metamorphic sedimentary rocks, volcanic rocks, and pyroclastic rocks, as well as Cenozoic Quaternary alluvial, alluvial, sloping, and residual clay, loam, and sandy gravel layers, which are mainly distributed in river valleys and mountain basins. The foundation rock is mostly granite, and the thickness of the loose layer is small, mostly less than 20m. A small number of residual slope deposits are distributed on the top of the hill and the hillside, and the thickness varies greatly.

There are faults in the region, mostly in the northeast, northwest, and nearly north-south directions. The major faults include the Northeast gumau worji fault and the nearly East-West zuku takalafia fault, which extend more than 50km and belong to the compression torsion strike fault. Another fault extends for 5 ~ 30km. Zuku dumbu is a large area in which ring structures are developed, mostly formed by the emplacement and cutting of the Precambrian basement by the Mesozoic granite body.
Granitic gneiss and migmatitic gneiss are widely distributed in the East and North East of the plateau. Since the Mesozoic, the Jos Plateau has been continuously uplifted, and the regional thermodynamic metamorphism has been accelerated. Precambrian ancient biotite granite has been continually transformed, the protolith has been transformed and crystallized, and there is a large variety of granite gneiss. Metamorphism and migmatization in this area have given rise to lead-zinc, iron ore, niobium tantalum, cassiterite, graphite, and other minerals.

mining in Nigeria

As a result of the Joss-Baoqi niobium-tantalum polymetallic metallogenic belt, metallogenic geological conditions in the area are relatively favorable. In the Precambrian and Mesozoic, with extensive magmatic intrusion, volcanic eruption and metamorphism, a large number of metal minerals were formed in the Jos Plateau. Among them, niobium-tantalum and tin ores are the most widely distributed.

A series of types of ferroniobium and tin deposits are related to magmatism, primarily the magmatic-hydrothermal type and the sub-volcanic hydrothermal type. Tin in the ore exists primarily as symbiotic and associated components with iron, copper, tungsten, niobium, and tantalum, and the main metal minerals are cassiterite, niobite, chalcopyrite, and pyrite. The main types of cassiterite are cassiterite quartz veins and cassiterite sulfide ore, with a small amount of associated quartz vein type wolframite.

There was granitization, silicification, and pyritization of the main wall rocks. The main metal mines in the area are cassiterite, niobium iron ore, copper, lead and zinc mines. There are also many gemstone mines in the area, such as granite pegmatite type beryl, tourmaline and other gemstone mines.

This area is a typical inter-mountain basin topography. Mountains are mainly distributed on both sides of the area. The landform types in the area are mainly alluvial-proluvial landforms, river valley landforms and weathered residual landforms. The parts near the mountains are mainly affected by sheet flow, forming different Types of eroded slopes and slope skirts, rills and incisions are developed locally on the front of the mountain, and gullies can be seen sporadically. In the area, the floodplains are developed on both sides of the river, forming a typical meander on the floodplain, and the terraces are not developed, and the alluvial and proluvial landforms are most prevalent. Due to the long-term denudation of the high plains of Qiaosi, the Quaternary strata in the area are thin.

mining in nigeria

Generally, ore-bearing horizons are located in the weathering crust at the top of cassiterite-bearing granite. The length of the ore body generally varies from several hundred meters to several kilometers, and the thickness of the ore body varies from several meters to several tens of meters. Lenticular output, the ore types are mainly earthy and semi-loose, and the cassiterite content is generally between 0.10kg/m3-0.8kg/m3, often accompanied by W, Nb, Ta, Ti, etc.

In this deposit mining in Nigeria, the surface ore body has an exposed length of about 3000 meters, a width that ranges from 50 to 300 meters, and an average width of about 100 meters. Since there is no previous geological work, the weathering crust The thickness is unknown, and local mining is mainly concentrated on the weathered soil-like ore bodies on the surface, and the semi-loose weathered crust has not been elutriated. Therefore, the thickness of the ore body is unknown, and further exploration and verification work is required. According to reports, the grade of cassiterite tested in the past is about 0.6kg/m3.

Work suggestion：

Using RC drill or DD drill, according to the spacing of 80 × 80m, the depth is controlled by the side, and the available resource reserves are submitted according to the specification requirements.