INTRODUCTION

Our nation Nigeria, although partially dependent on mining explorations for its economic growth has a pressing challenge that remains largely overlooked. Mining Waste is a hidden untapped treasure that could revolutionize our economy whilst protecting the environment. Hence,  the concept of a circular economy in mining, whereby waste transformed into wealth, reduces environmental hazards, and fosters sustainability.

WHAT EXACTLY IS A CIRCULAR ECONOMY IN MINING?

A circular economy moves away from the traditional ‘take-make-waste’ model. Instead of discarding resources after use, materials are reused, recycled, and regenerated (Yiqing Zhao et al., 2011). In mining, this means utilizing waste products as valuable resources.

Mining waste typically includes rocks, tailings, slags, and water contaminated during mineral extraction. While these materials have historically been abandoned or disregarded, advancements in technology and sustainable practices now allow them to be repurposed for economic and environmental gain. Imagine a Nigeria where the mountains of tailings from artisanal mining sites become raw materials for construction such as Bricks, Concrete, Foam ceramic and so on.

NIGERIA’S MINING WASTE PROBLEM: A GROWING CONCERN

Nigeria’s mining sector is expanding, particularly with activities in gold, lead, zinc, lithium, and other minerals. However, unregulated mining, especially artisanal mining generates an immense amount of waste and improper disposal exacerbates land degradation, water pollution, and health risks. In states like Zamfara, Niger, and Plateau, massive dumps of mining tailings dot the landscape, posing serious health risks due to heavy metals like lead, cadmium, and arsenic causing the death of Over 400 children due to exposure to lead-contaminated dust from artisanal gold mining waste (BBC News, 2010). Similarly, in Plateau State, abandoned tin mines have left behind pits that accumulate contaminated water, posing long-term environmental and public health risks (Ogundiran & Osibanjo, 2009).

Take a look at the numerous granite quarries spread throughout the country, their inert waste has been classified on the European List of Waste under code 01 04 13, “wastes from stone cutting and sawing other than those mentioned in 01 04 07” (European Comission, 2000). It has a heavy environmental impact due to its adverse effect on soil permeability, for it hinders water seepage to the lower layers, which in turn affects aquifer recovery and plant life. It also constitutes a risk to human health due to the small percentage of crystalline silica in the fines which, if inhaled, may cause lung disease of varying severity (Singh et al., 2016).

TRANSFORMING MINING WASTE INTO ECONOMIC OPPORTUNITY

1. Recycling Tailings for Construction and Infrastructure

The mining circular economy promotes sustainable practices by recycling and repurposing mining waste and byproducts. Materials like slag, fly ash, and calcium sulfate are utilized in construction and manufacturing industries, reducing waste and environmental impact. Residual heat is repurposed for heating and fermentation energy. Treated wastewater from mining operations serves as cooling water or process water, conserving resources and preventing pollution. This approach addresses resource scarcity, minimizes waste, mitigates environmental damage, and enhances resource efficiency, contributing to sustainable economic development.

Mining tailings, particularly from granite or limestone extraction, can be processed into aggregates for building roads, bridges, and housing. When managed appropriately, these materials reduce dependency on virgin resources like river sand, which are being overexploited. The abandoned tin mine tailings could be repurposed for road construction projects, particularly in rural areas where infrastructure remains underdeveloped. This approach creates jobs whilst addressing Nigeria’s critical infrastructure deficit.

Repurposing mining tailings for construction offers economic and environmental benefits, but it also raises health and safety concerns due to residual toxins like silica dust, heavy metals, and radioactive elements. Inhalation of crystalline silica can cause lung diseases such as silicosis, while exposure to heavy metals like lead and arsenic poses serious health risks. Therefore, rigorous safety standards must be enforced to ensure safety in repurposing the waste, including;

• Comprehensive Material Testing: Ensuring tailings are free from hazardous levels of toxins before use.
• Proper Processing Techniques: Using encapsulation, stabilization, and chemical treatment to neutralize harmful substances.
• Workplace Safety Measures: Implementing dust control systems, protective gear, and regular health monitoring for workers.
• Regulatory Compliance: Establishing strict national guidelines aligned with global best practices (e.g., WHO, EPA) for safe waste utilization

Other uses for tailings include; 

• Shotcrete: Tailings can be used to make commercial shotcrete.
• Concrete: Tailings can be used to make concrete products for mine roads. 
• Insulation: Tailings can be used to make insulation. 
• Foamed products: Tailings can be used to make foamed products