| en |
Utilization of neutralized spent sulfuric acid pickle liquor from metal treatment in cement production
Jarosz-Krzemińska, E.; Helios-Rybicka, E. & Gawlicki, M.
Abstract
The research addresses the issue of utilization
of neutralized spent sulfuric acid pickling liquor, deposited
in 1.62 ha lagoons, derived from steel industry, in cement
production. Physical–chemical characteristics of the
investigated waste revealed low levels of contaminants
with the exception of sulfate anions. However, the presence
of CaSO4⋅2H2O revealed a new utilization option for the
investigated waste. A key part of the research involved
studying the usability of stored waste as a substitute of
natural gypsum, acting as a set retarder in cement production.
Cement was prepared by grinding Portland clinker
with the addition of waste gypsum and then was subjected
to the examinations of initial setting time, specific surface,
water demand and compressive strength. The analysis of
mechanical and physical properties revealed that the tested
cement with the addition of waste meets standard
requirements for Portland cement. Furthermore, the study
of natural radioactivity of the waste did not reveal a rise in
the level of radionuclides, thus confirming that the investigated
waste can be used for the production of construction
materials used in buildings intended for human residence.
Utilization of the deposited wastes can help eliminate the
environmental hazards regarding sulfuric acid pickle liquor
waste and can also provide a low-cost resource of waste
gypsum, which can be widely used in the production of
construction materials.
Keywords
By-product gypsum; Cement; Portland clinker; Spent pickling liquor; Set retarder
|
