Cypress Development Corp: Cypress Development Announces Further Advancement in Chloride Leaching for Clayton Valley Lithium Project in Nevada Cypress Development Corp. ( rdand 16 th2020 news releases, the Company initiated an investigation into chloride-based leaching and the potential economic and environmental benefits over sulfide-based leaching. Progress to date indicates a positive alternative to a sulfate-based approach and merits consideration for the Company's upcoming pilot plant program. Test work completed on 200- to 400-g samples of claystone used hydrochloric acid (HCl) and sodium chloride (NaCl) brine as the leach solution. Test results from this work determined the optimum parameters for leaching temperature, acid strength, and retention time. The data were used to conduct a test on a 33 kg sample of claystone which yielded greater than 81% extraction of the lithium into solution. The Company identifies this as a starting point for the pilot plant program to expand upon these results and demonstrate that they are sustainably operational on a larger scale.