Abstract
In this work, experiments were performed to determine the
filterability of calcium carbonate produced with an
alternative calcium carbonate production concept. The
concept uses steelmaking slag as raw material and has
potential to fix CO2 emissions and utilize steelmaking
slag, simultaneously. As calcium carbonate is
precipitated in a solution containing ammonium chloride,
calcium chloride, and ammonia, the product needs to be
washed and hence filtered. In this work, different
separation processes, including washing, filtering, and
drying, were tested on two calcium carbonate slurries
produced from steel converter slag and CO2 by a
laboratory-scale pilot facility, with the aim of
obtaining a solid product with a low chloride content
using a minimum amount of washing water. The order of
maximum filtration rates achievable of the calcium
carbonate slurries was determined by experimental work.
The tests included pressure filtration and vacuum
filtration and the test series contained altogether 21
different filtration cycles with varying combinations of
filtering, washing, and drying steps. The filtered cakes
were analyzed by their residual moisture content,
chloride content, and conductivity, and the filtrates by
their residual solids content, chloride content, and
conductivity. Pressure filtration gave a high capacity
(400-460 kg/m2h) and a low cake residual moisture content
(12-14 wt-%). Vacuum filtration gave slightly higher
filtration rates (500-610 kg/m2h at the lowest residual
chloride contents of the cakes), but the cake residual
moisture also stayed higher (25-26 wt-%). As the vacuum
filtration tests used a filter cloth with higher
permeability than that of the pressure filtration tests,
a slightly higher filtration rate was expected. However,
both filtration technologies seem suitable for filtering
and washing calcium carbonate prepared with the studied
method as a residual chloride content as low as 10 ppm of
the filtered solids can be achieved with quite a small
amount of washing water and the filtration rate is fast.
Original language | English |
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Article number | 6 |
Journal | Frontiers in Energy Research |
Volume | 4 |
DOIs | |
Publication status | Published - 2016 |
MoE publication type | A1 Journal article-refereed |
Keywords
- mineralization
- carbon dioxide
- CCU
- utilization
- filtration
- PCC
- GCC