Abstract
This study focused on membrane filtration of neutralized
pond water, which may be necessary when good quality
water is required for hydrometallurgical processes.
Neutralized mine water can still have fairly high metal
and sulphate levels, which can hinder discharge and reuse
possibilities. Both nanofiltration and reverse osmosis
are effective in removing metals and sulphate, but
scaling can be a severe problem. Microfiltration as a
pre-treatment method, although meant for particle
removal, seemed to decrease the amount of scalants, thus
delayed scaling on the membrane surface and increasing
water recovery for both nanofiltration and reverse
osmosis. It is possible that the presence of particles in
the feed water promoted crystal growth in the turbulent
flow and caused the removal of dissolved constituents.
Alternatively, supersaturation could have occurred,
allowing microfiltration to remove the scalants as
particles. The Liqum sensor indicated that redox values
started to increase again just before scaling began due
to precipitation in the supersaturated membrane
concentrate solution. Thus, the sensor seemed to provide
real time, in-situ, early-stage scaling warning.
Original language | English |
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Pages (from-to) | 193-198 |
Journal | Mine Water and the Environment |
Volume | 36 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Jun 2017 |
MoE publication type | A1 Journal article-refereed |
Funding
Tekes, VTT Technical Research Centre of Finland Ltd, Outotec, Sofi Filtration, Pöyry, and Liqum are all acknowledged for their financial support of the project.
Keywords
- microfiltration
- nanofiltration
- neutralizing pond water
- real-time measurements
- reverse osmosis
- scaling