Advancements in Tin Recovery From Scrap Printed Circuit Boards

VANCOUVER, BC / ACCESSWIRE / June 24, 2021 / EnviroLeach Technologies Inc. (the "Company "or "EnviroLeach"), (CSE:ETI)(OTCQB:EVLLF)(FSE:7N2) is pleased to report the results of an ongoing research and development program to recover tin from scrap printed circuit board assemblies (PCBAs).

The recent phase of the research program was conducted using low-grade PCBAs and focused on locked-cycle tests and further process development to determine preliminary economic viability. The lock-cycle tests were designed to assess the reusability of the leach solution and address the potential accumulation of impurities. This important step in process development significantly reduces the reagent consumption and related costs. It also allows for predictable process control, as well as the development of the final process flow sheet for subsequent pilot and full-scale plant design and engineering. Locked-cycle reusability tests demonstrated continuous recoveries averaging 84.2% over 16 cycles confirming the reusability of the leach solution. Previous laboratory tests performed using high-grade scrap PCBA concentrate material produced up to 92.6% tin recoveries (see Company news release dated November 5, 2020).

Low-Grade PCBA Tin Locked-Cycle Reusability Tests

Cycle Number	Calculated Tin Head-Grade %	Tails Tin Grade %	Average Tin Recovery %
1 to 4	6.33	1.05	86.4
5 to 8	5.74	1.32	80.1
9 to 12	4.27	0.93	81.8
13 to 16	6.07	0.92