Process for mining sand or gravel from a sand or gravel deposit at the bottom of a body of water

摘要

sand removal process. The present invention relates to a process for mining sand or gravel from a sand or gravel deposit at the bottom of a body of water, comprising the following steps: i) providing a mining machinery capable of transporting sand or gravel from a mining position at the bottom of said water to a desired location, said mining position being at a relatively lower level than the upper limit of said sand or gravel deposit to be mined; ii) provide a water injection medium capable of injecting water into the sand or gravel deposit; iii) injecting water into said deposit by said injection means, so that said injection is performed substantially directly on the surface of said deposit, in a selected amount and flow rate so that the sand or gravel and the injected water form a liquefied layer, said liquefied layer being capable of flowing under the influence of gravity from said deposit site to the lower level mining position; and iv) mining said sand or gravel by said mining machinery, after said sand or gravel has drained from said deposit to said mining position.