(LA) SEPARATION OF SULPHUR DURING LEACHING IN A PROCESS FOR THE RECOVERY OR VALUE METALS FROM SUPHIDE- BASED ORES

(LA) ຂັ້ນຕອນສໍາລັບການລ້າງໂລຫະມີຄ່າຈາກແຮ່ທາດຊຸນຟິດ, ປະກອບມີຂັ້ນຕອນຂອງການລ້າງແຮ່ທາດ ທີ່ມີສານແຍກທາດລະລາຍເຊິ່ງປະກອບມີຄໍລາຍ, ທາດປ່ອຍອົກຊີ ແລະ ກົດເກືອທີ່ຖືກເປີດເຜີຍ. ຕົວຢ່າງຂອງຄໍລາຍປະກອບມີໂຊດຽມ ແລະ ແມັກນີຊຽມຄໍລາຍ. ຕົວຢ່າງຂອງທາດປ່ອຍອົກຊີປະກອບມີີ ຄໍເລດໂຊດຽ້ມ ແລະ ຄໍລິນ. ຢູ່ໃນໂຄງສ້າງ, ຂັ້ນຕອນປະກອບມີການສະກັດໂລຫະມີຄ່າຈາກທາດຊຸນທີ່ມີຂັ້ນຕອນດັ່ງນີ້: ການລ້າງແຮ່ທາດດ້ວຍສານແຍກ ທາດລະລາຍທີປະກອບມີຄໍລາຍ, ທາດປ່ອຍອົກຊີ ແລະ ກົດເກືອ; ການແຍກໂລຫະມີຄ່າຫຼາຍໃນສານທີ່ໃຊ້ລ້າງຈາກແຮ່ທາດໃນການແຍກທາດແຫຼວ-ແຂງ ທໍາອິດ; ການປ່ອຍອົກຊີ ແລະ ເປັນກາງຂອງໂລຫະມີຄ່າຫຼາຍໃນສານທີ່ໃຊ້ລ້າງ; ແລະ ການແຍກການລະລາຍຂອງຄໍລາຍຈາກສານທີ່ໃຊ້ລ້າງເພື່ອໃຫ້ໄດ້ການແຍກທາດແຫຼວ-ແຂງຂັ້ນສອງ. ໃນໂຄງສ້າງນີ້, ຄໍລາຍເປັນແມັກນິຊຽມຄໍລາຍ ແລະ ສານແຍກທາດລະລາຍທີ່ຖືຜະລິດຂື້ນ.

(EN) A process for leaching a value metal from a sulphide-based ore, comprising the step of leaching the ore with a lixiviant comprising a chloride, oxidant and hydrochloric acid is disclosed. The leaching is controlled, by use of low concentrations of hydrochloric acid ( less than 18% ( mass ratio )) and redox potential, to effect formation of hydrogen sulphide from the sulphide-based ore. The hydrogen sulphide is stripped from the leach solution, thereby reducing the amount of sulphur or sulphate generated in the leach to very low levels. Examples of the chloride include sodium and magnesium chloride. Examples of the oxidant include sodium chlorate and chlorine. In embodiments, the process comprises recovery of a value metal from a sulphide-based ore comprising the steps of: leaching the ore with a lixiviant comprising chloride, oxidant and hydrochloric acid, said leach forming hydrogen sulphide which is stripped therefrom; separating a value metal-rich leachate from the ore in a first solid-liquid separation; oxidizing and neutralizing the value metal-rich leachate so obtained; and separation of solution of chloride from the leachate so obtained in a second solid-liquid separation. In an embodiment, the chloride is magnesium chloride and lixiviant solution is regenerated.