|
|
|
|
 |
 |
|||
 
|
Definition Solution Mining: The use of water or hot water to dissolve a desired mineral from a geological ore zone into solution through directional or vertical boreholes or abandoned underground mine workings. Solution mining can be used for many water soluble minerals, including:
Process Potash solution mining in Saskatchewan is based upon a technique developed by Byron Edmonds, Alice and James Dahms, and Edward Helvenston for the Pittsburg Plate Glass Company (PPG) in the early 1960's (United States Patent Number 3,096,969). The process is initiated by drilling two wells (very similar to oil and gas wells) spaced between 60 and 80m apart through the potash resource. Upon completion of the drilling the following steps are usually followed to develop a solution mining cavern: 1. Sump Development. Ambient fresh water is injected to dissolve a sump area within the NaCl salt at the base of the solution mining cavern. The sump allows insoluble materials settle within the cavern to avoid affecting the solution mining process. (Figure 1) 2. Cavern Connection and Roof Development. Upon completion of sump development, the fresh ambient water injection is continued to solution mine the two individual caverns within the NaCl salt at the base of the solution mining cavern. A special mining technique is used to cause the individual caverns to connect or merge. Upon establishing connection solution mining is continued within the NaCl salt at the base of the solution mining cavern to create additional roof area for the subsequent potash solution mining. (Figure 2) 3. Primary Mining. Once the cavern roof is developed, primary mining is initiated by creating a 1.5 -- 3.0 meter casing cut or perforation into the potash mineralized zone. Heated fresh water is injected to dissolve both KCl (Sylvite) and NaCl (Halite). As the KCl and NaCl are dissolved into solution creating a void at the top of the cavern, the oil blanket migrates upward into the cut area and flows outward laterally controlling the vertical growth of the cut as additional salt is dissolved. (Figure 3) 4. Secondary Batch Mining. As the potash mining progresses to the top of the Patience Lake potash zone, secondary mining can be initiated. Heated, saturated NaCl brine is injected instead of fresh water. Only the KCl is dissolved into solution and small amount of NaCl will precipitate from solution. The cavern production rate will decrease due to the slower dissolution rate of KCl into NaCl brine. Secondary mining and cooling pond potash recovery require less energy than primary mining. (Figure 4)
Typical Cavern Arrangement Using the Edmonds et al method, each Cavern requires two wells. Each well is about 1600m deep and is drilled similar to an oil or gas well. In this representation, 18 wells (9 Caverns) are shown being directionally drilled from a single surface location. This is called pad drilling or a cavern cluster. Solution Mining Flow Sheet |
| Suite 1238 - 200 Granville Street, Vancouver, BC, Canada, V6C 1S4 |
| HomeCorporateNewsPotashProjectsInvestorsQwikReportContactDisclaimerSite Map |
