The beneficiation process of African chromium ore is driven by ore characteristics (such as embedded particle size, associated minerals) and resource development goals. In recent years, it has been continuously innovated in efficiency improvement and environmental protection transformation. This article analyzes the mainstream process, equipment application and technical bottlenecks.

‌1. Mainstream beneficiation process‌

African chromium ore is mainly layered chromite and pod-shaped chromite, and the beneficiation process revolves around "improving grade and reducing impurities":

‌Gravity separation method‌ (accounting for 65%)

‌Core equipment‌: spiral chute (processing coarse-grained ore), jig (recovering medium and fine-grained ore).

‌Typical case‌: The Bushveld Mine in South Africa adopts the "two-stage spiral chute + shaking table" combined process, and the concentrate Cr₂O₃ grade is increased from 28% to 42%, and the recovery rate exceeds 85%.

‌Magnetic separation method‌ (accounting for 25%)

‌Applicable scenarios‌: fine-grained embedded ore (such as the Big Rock Wall Mine in Zimbabwe). ‌Equipment upgrade‌: High-pressure roller magnetic separator (background magnetic field strength 1.6T) replaced the traditional drum magnetic separator, and the chromium loss rate of tailings was reduced from 12% to 5%.

‌Combined process‌ (accounting for 10%)

‌Gravity-magnetic combination‌: Sudan Red Sea mining area adopts the "spiral chute pre-selection → wet strong magnetic separation" process to treat high-impurity ore containing silicates.

‌Flotation test‌: South Africa's Mintek Research Institute tested anionic collectors (such as sodium oleate), with a target recovery rate of over 90%, but it has not yet been applied on a large scale.

‌2. Core equipment and technological breakthroughs‌

African mineral processing equipment presents a coexistence of "high-end imports" and "local transformation":

‌Sorting equipment‌

‌Intelligent sorting machine‌: Chinese mining companies in Zambia introduced the ‌TOMRA XRT ore sorting machine‌, which uses X-rays to identify chromite and gangue, with a single machine processing capacity of 150 tons/hour and energy consumption reduced by 30%.

‌Modular jigging unit‌: Zimbabwe promotes containerized jigging units, and the installation period is shortened from 3 months to 2 weeks.

‌Crushing and grinding equipment‌

‌High-pressure roller mill‌ (HPGR): The Sylvania mining area in South Africa uses equipment with a roller diameter of 2.4m, and the crushing energy consumption is 40% lower than that of traditional ball mills.

‌Vertical stirred mill‌: Used for re-grinding of fine-grained ores, and the product particle size of -0.074mm accounts for more than 95%.

‌Environmental protection equipment‌

‌Wastewater circulation system‌: South Africa requires that ore dressing plants be equipped with "neutralization precipitation + membrane filtration" devices, and the hexavalent chromium concentration is reduced from 15mg/L to below 0.1mg/L.

‌Dust recovery tower‌: Zimbabwe uses a combination of cyclone dust removal + bag filtration, reducing dust emissions by 80%.

3. Technical Challenges and Future Trends‌

‌Realistic Bottlenecks‌

‌Ore Complexity‌: African chromium ores are often associated with platinum group metals, and the sorting process needs to take into account the recovery of multiple elements (such as the UG2 ore layer in South Africa).

‌Power Shortage‌: Zimbabwe's ore dressing plant was forced to install diesel generators due to power restrictions, resulting in a 25% equipment downtime rate.

‌Innovation Direction‌

‌Intelligent Control‌: South Africa piloted AI algorithms to optimize sorting parameters (such as feed volume and water flow rate), with the goal of increasing the recovery rate by 3%-5%.

‌Low-carbon Transformation‌: The EU funded Morocco to build a solar-driven ore dressing plant, reducing CO₂ emissions by 12,000 tons per year.

‌Localization Breakthrough‌

‌Equipment Imitation‌: Nigerian machinery factories imitated Chinese spiral chutes, reducing costs by 40%, but the life span was only 60% of imported products.

‌Technical Training‌: The China-Africa Mining Alliance established a ore dressing technical school in the Democratic Republic of the Congo, with an annual training capacity of 500 people.

‌Conclusion‌

Chromium ore beneficiation in Africa is transforming from "extensive sorting" to "fine and green", but technology dependence, energy constraints and talent gap are still key constraints. In the future, through intelligent upgrading, clean energy substitution and local industrial chain cultivation, Africa is expected to occupy a more active position in the global chromium resource market.