Mixing Phosphate Mining Waste: A Safety Solution

Have you ever thought about what happens to the waste left over from mining? Phosphate mining, in particular, generates a lot of waste, including tailings and waste rock. These are usually stored in dams, but these dams can be unsafe. Brazil has seen many dam ruptures, which is why finding better ways to handle this waste is so important. One idea is to mix tailings and waste rock together before storing them. This is called co-disposal. Scientists have looked at this method for other mining wastes, but not much has been done for phosphate mines. So, a team of researchers decided to study this. They wanted to find the best mix of tailings and waste rock. They did tests to see how strong the mixed waste was compared to the individual materials. The results showed that mixing these wastes together made them much stronger, especially when it comes to something called the internal friction angle. This is important because it helps keep the waste from sliding around.The mixed waste also had a special kind of strength, called cohesion, that was between the strength of the tailings and the waste rock. This was because of something called suction effects, which happen when the waste isn't completely wet. The scientists also looked at the waste under a microscope and used X-rays to see how the tiny parts of the mixed waste were different from the individual parts. This helped them understand why the mixed waste behaved differently. This study is a big step in making phosphate mining waste disposal safer. It shows how mixing tailings and waste rock can improve the safety and mechanical behavior of the waste.