Document Type

Technical Report

Publication Date

8-1-1980

Keywords

Coal slurry, pipelines, large volumes of coal, transportation

Abstract

The research program was designed to accomplish three major objectives. These were tot 1) identify and characterize the water quality changes that will occur as a result of the movement of western coal by slurry pipeline; 2) determine the feasibility of utilizing poor (impaired) quality water, such as municipal and industrial effluents, as the slurry medium, and: 3) determine the treatment measures applicable for restoring the slurry wastewater quality to acceptable levels, if required. The focus of the research program was generic rather than specific for any particular pipeline. Consequently, the emphasis was on establishing general ranges of data rather than on absolute parameter values for a specific coal and water source. Six variables were established for the experimental work. These are coal source, influent water quality, slurry solids concentration, mixing rate, detention time, and the type of environment to which the slurry was to be exposed. One run for each set of data was conducted with distilled water to provide comparable data among coal sources as a function of time. Well waters, surface water and secondary-treated municipal wastewater were also used as water sources. Three sources of coal were used in the experimental work. Thirty, forty, fifty and sixty percent solids slurries were used to determine the effects of slurry solids concentrations on water quality. Two mixing rates were used to determine the effects of this variable on the characteristics of the slurry wastewater. Aerobic, anaerobic and sequential aerobic-anaerobic environments were utilized to identify the impact of this variable on water quality. The water quality parameters measured included alkalinity, aluminum, biochemical oxygen demand, calcium, chemical oxygen demand, chromium, copper, dissolved solids, iron, lead, manganese, magnesium, mercury, nitrate, pH, phosphate, potassium, silica, specific conductance, sodium, sulfate, titanium, total hardness and zinc. The results of the investigations indicated that relatively high concentrations of hardness, dissolved solids, sulfate and sodium will result from the slurry pipelining of the western coals investigated. Lower concentrations of aluminum, chloride, lead, nitrate and titanium can be expected in the slurry wastewater. The concentrations of several parameters were below the detectable limits of the test procedure used. These included chromium, copper, iron, manganese, mercury, phosphate and zinc. The data for the parameters identified are included in the report as functions of coal source, water source, percent slurry solids, mixing rate, detention time, and the type of environment used. Comparisons of the data for the six variables are also included.

Report Number

PUB073

Page

376

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