While U3O8 Corp. has achieved a major milestone in reporting an initial uranium resource estimate, it is still in the exploration stage. Ongoing exploration work aims to increase our resource and determine whether we have found an economic uranium deposit. Only thereafter can we undertake a formal commercial and environmental assessment. Provided these assessments conclude that the deposit is viable, an application can be made to the Guyanese authorities for a mining license to build a mine.
Should U3O8 Corp. define a uranium deposit of economic size in Guyana, a prospective mine could cover an estimated 2,000 hectares or well under 1% of the original land surface covered by its Reconnaissance Permits.
Mine planning involves all aspects of mine development from initial extraction through to mine closure, waste management and restoration of lands for future use.
3. Waste Management
4. Water Management
5. Regulatory and Environmental
6. Mine Closure and Land Restoration
Uranium ore is extracted from the ground in underground mines or open pits depending on the depth of the deposit. In U3O8 Corp’s case, uranium in the Kurupung area begins about 20 metres from surface and continues for over 200 metres below surface. The ore body remains open at depth, therefore, the uranium could extend considerably further below surface. Since the uranium-bearing bodies start so shallow, they could initially be mined in open pits while the deeper extensions of the bodies could be mined in underground operations.
During mining, radiation from radon gas requires constant monitoring. Radon is a radioactive gas that occurs naturally everywhere – in soil, water and air – and comes from the natural breakdown of uranium in soils and rocks. In open pit mining, there is sufficient natural airflow to prevent the accumulation of dangerous levels of radon. Underground mines have extensive forced ventilation systems that supply fresh air to ensure that radon gas does not accumulate to dangerous levels. For example, the Australia’s Olympic Dam underground mine averages <100 millirem (mrem)/year and Canada’s very high-grade underground uranium mines average 300 mrem/year – well below the regulatory limit of 5,000 mrem.
Infrastructure is a key component of mine development. There are a number of green options to reduce environmental footprint of a mine operation should one be developed in Guyana for U3O8 Corp’s Kurupung deposit, such as:
- Run-of-the-river hydropower facility near the mine (eg. Guyana Goldfield’s Cuyuni 10-15 megawatt hydroelectric project) that causes minimal backup of the river in contrast to conventional hydro dams, while also eliminating the environmental footprint of high tension power lines linked to the national grid;
- A small solar farm as a potential power source; and
- Making use of the existing navigable rivers and airstrips in Guyana for the transport of equipment and construction materials.
Milling and Processing
Uranium in U3O8 Corp’s exploration area in the Kurupung Batholith is contained within a hard, granitic rock that would need to be blasted in either an open pit or underground mining scenario. The fragments of blasted rock generally range from the size of a tennis ball to that of a Pilates exercise ball. The uranium ore would then be loaded onto trucks in the mine and transported on well-maintained earth roads moistened by water sprayer trucks to minimize dust (in the same way that water sprayer trucks are used in normal road construction) to the processing plant.
At the plant-site, the rock would be crushed into golf-ball sized fragments that are fed into a mill through a large, horizontal, rotating steel cylinder in which the rock fragments are ground into a fine slurry that has the consistency of watery mud. Thereafter, the slurry would enter the plant where the uranium would be extracted from the rock, concentrated, dried and processed into uranium oxide (U3O8) that is a yellow paste also called “yellowcake”. The yellowcake would be sealed in 45-gallon or 200-litre steel drums for shipment overseas for further processing into fuel for nuclear power plants.
A potential uranium mine in Guyana would produce yellowcake, which could be shipped to refineries abroad via the Atlantic Ocean to eastern USA, Canada or Western Europe.
Approximately 85% of the uranium in deposits that are geologically similar to U3O8 Corp’s Kurupung project, can typically be commercially extracted. The muddy slurry from which the uranium has been extracted, called tailings, contains only about 15% of the uranium contained in the original deposit. The radioactivity of the tailings should be similar to the natural radioactivity of the Kurupung granite. The tailings would be piped to a dam located near the processing plant for long-term storage.
Tailings are contained in regulatory approved, monitored dams, which are similar to earth water reservoirs in basic design:
- The site near the mine is excavated down to the impermeable clay layer that lies between the soil and the underlying granitic rock.
- The depression is surrounded by an engineered rock and earth wall that is designed to withstand 100-year flood events.
- Modern dam walls are constantly monitored for any potential weakness that measure minute changes in fluid pressure that would indicate that a weakness is developing in the wall.
- The dams are typically covered with water and aquatic vegetation, which further reduces radioactivity (less radioactivity than the Kurupung naturally emits now).
Based on exploration to date, the uranium-bearing rock in the Kurupung appears to contain:
- Negligible amounts of harmful elements such as arsenic, selenium and mercury;
- Very little sulphide, which means minimal risk of generating sulphuric acid and leaching of metals from the oxidation (“rusting”) of sulphides in the rock; and
- Significant quantities of calcite that ensure that any sulphuric acid generated through oxidation of the rock would be neutralized.
In designing the process to be used for the extraction of uranium from the ore, an early test is done to determine the environmental effect on fish and water fleas in discharge water in a pilot processing plant. Extensive testing and treatment is undertaken to meet strict discharge standards and water quality (including radiation) before any excess water is released to the environment.
The amount of water used in the processing of uranium ore is not significantly different than the amount used in processing plants for other minerals. The majority of water in the processing plant is re-circulated within the processing facility.
Regulatory and Environmental
Canadian mining and exploration companies are subject to regulations and standards in both the host country and Canada. Canada is a major player in global mining and exploration and has taken a leadership role in adopting some of the most stringent regulations and corporate social responsibility (CSR) standards at home and overseas.
Canadian agencies are supporting host countries to expand governance capacity. For example, Guyana’s Environmental Protection Act was developed with support from the Canadian International Development Agency. The Canadian government has introduced a government CSR policy for the Canadian exploration and mining sector operating abroad. As well, a Canadian industry-led set of CSR guidelines, called e3 Plus, was recently introduced to help exploration companies continuously enhance their social, environmental and health and safety practices.
The International Atomic Energy Agency requires that all countries exporting uranium sign the Non-Proliferation Treaty and the Safeguards Agreement to ensure that uranium is only used for peaceful purposes. Guyana is among the recognized states around the world that are party to the Non-Proliferation Treaty and Safeguards Agreement.
As is the case with any mining venture, environmental approvals must be attained prior to proceeding with mine development. Mining companies must comply with environmental, safety and occupational health standards, which are increasingly governed by international standards and external audits. Many mining companies are ISO 14001 certified – the world’s most recognized environmental management framework.
Environmental studies are initiated during the exploration phase and are completed prior to the feasibility study, which is when an assessment is made whether to proceed with a mine development. Guyana’s Environmental Protection Act requires an Environmental Impact Assessment and a public consultation period as part of the regulatory review process, prior to a decision being taken on the permitting of a mine.
U3O8 Corp. has adopted an environmentally-oriented exploration approach from the start. We aim to minimize the environmental footprint of our work by using and improving existing exploration roads, limiting disturbance around drill pads, ensuring responsible management of drill core and cuttings and implementing sound policies and precautionary measures to create a safe and healthy workplace.
Mine Closure and Land Restoration
Upon decommissioning of a mine, wells are sealed or capped, process facilities removed, tailings are covered permanently with enough clay, soil and vegetation growth to reduce radiation levels to near or below those naturally occurring in the region, evaporation ponds are re-vegetated, and the land is restored for future use.
A routine requirement is that the company arranges a guaranteed bond at the outset of mining. That bond is held by the government as security for the estimated cost of rehabilitation upon mine closure. Canadian accounting standards require a “fully-costed plan” (including ecosystem viability, radiological safety and landform stability) to be prepared annually during the operation of a mine and a financial provision for this estimate is included on the balance sheet.
Source: World Nuclear Association, Health Canada