Microwave solidification of uranium tailings pond beach surface is a technical means for the treatment of radioactive uranium tailings pond beach surface microwave heating In order to improve its stability and safety, the beach surface of tailings pond shall be solidified. The following is a detailed analysis of microwave curing of uranium tailings pond beach surface:

1、 Technical background

In the process of uranium mining and metallurgy, a large number of waste rocks and tailings will be produced. These waste rocks and tailings contain more than dozens of radionuclides, which are characterized by large quantity, long half-life and wide distribution. As the storage place of these waste rocks and tailings, the safety and stability of uranium tailings pond have a direct bearing on the environment and public health. However, traditional governance methods often have problems such as poor effect, high cost and long cycle. Therefore, it is particularly important to explore new governance technologies.

2、 Technical Principles

The microwave curing technology of uranium tailings pond beach surface utilizes the characteristics of microwave heating, through the deep microwave heating system and the surface microwave heating system, the tailings pond beach surface is subject to layered and directional microwave curing treatment. In the process of microwave heating, the water, organic matter and other volatile substances in the tailings will be rapidly heated and evaporated. At the same time, melting and solidification reactions will occur between tailings particles to form stable solidified bodies. The solidified body has high mechanical strength and impermeability, and can effectively prevent the migration and diffusion of radionuclides.

3、 Technical characteristics

Fast heating speed: microwave heating has the characteristics of instantaneity and penetrability, which can quickly transfer heat to the inside of tailings to achieve rapid heating.

Short sintering time: due to the fast heating rate, the tailings particles can reach the melting and solidification temperature in a short time, thus shortening the time of the whole sintering process.

Timely control: The microwave heating process can be controlled by adjusting the microwave power, heating time and other parameters to ensure the consistency of the curing effect.

Sensitive reaction: microwave heating can stimulate the chemical reaction in tailings and promote the solidification reaction.

Strong penetrability: microwave can penetrate the surface of tailings and heat and solidify the interior to avoid the phenomenon that the surface is solidified but the interior is not.

High energy utilization rate: the energy loss during microwave heating is small, and the energy utilization rate is high.

Less secondary waste: less waste gas, waste liquid and other secondary waste are generated during microwave curing, which is conducive to environmental protection.

4、 Application examples

In recent years, China has made remarkable progress in microwave curing technology of uranium tailings pond beach surface. For example, in the 2021 "Unveiling the list and taking the lead" project issued by the Science and Technology Department of Hunan Province, the "Research and Development of Technologies and Equipment for the Treatment of Radioactive Uranium Tailings Pond" project led by Nanhua University and participated by Central South University, which is issued by CNNC 272 Uranium Industry Co., Ltd., includes the research and development of microwave curing machine for the beach surface of radioactive tailings pond. The project aims to achieve effective treatment, safety and stability of radioactive tailings pond beach surface through technological innovation and equipment upgrading.

5、 Summary

Microwave solidification technology of uranium tailings pond beach surface is a treatment method with broad application prospects. Through the application of this technology, the stability and safety of uranium tailings pond beach can be improved, and the harm of radionuclides to the environment and the public can be reduced. In the future, with the continuous development and improvement of technology, the microwave curing technology of uranium tailings pond beach surface is expected to be popularized and applied in more fields.

List of overall equipment parameters

1. Microwave power: 150kW (two 75kW high-power microwave sources);

2. Microwave frequency: 915 ± 10MHz;

3. Microwave irradiation area: 500 × 1000mm;

4. Horizontal movement distance of microwave heating chamber: 500mm;

5. Lifting distance of microwave heating chamber: 300mm;

6. Temperature measurement method: infrared temperature measurement;

7. Temperature control mode: automatic temperature control;

8. Sintering and curing frequency: 1h/sintered surface;

9. Sintering and curing depth: 150mm;

10. Microwave leakage intensity: ＜ 1m W/cm2, (far lower than the national standard of 5mW/cm2, GBZ 2.2-2007, Physical Factors of Occupational Exposure Limits for Hazardous Factors in the Workplace, to ensure full personal safety);

11. Circulating cooling water flow: ≥ 10m3/h ；

12. Dimensions of crawler mobile platform: platform 6m × 2.4m (length × width), crawler 5.5m × 0.5m (length × width);

13. Equipment weight: 15t (including 7t crawler mobile platform truck, 5t microwave source and microwave heater equipment, and 3t cooling water system).  

Can be customized according to customer needs