OFR 1993-18

Evaluation of Leonardite (Humalite) Resources of Alberta

Leonardite, humalite and humate are similar naturally occurring materials that are enriched in humic and other organic acids. These materials are of interest as a source of humic acids. Their major uses are as a soil amendment in agriculture and reclamation, and as a drilling fluid additive.

Deposits of these materials occur in Alberta, Saskatchewan, and possibly in British Columbia, but little has been compiled or published about their extent, quality and economic significance. This report attempts to summarize the available information for Alberta.

Leonardite is defined as a naturally occurring oxidized form of lignite coal that is rich in humic acids. Mineable deposits of leonardite exist in the Estevan, Saskatchewan area. In Alberta the term humalite (from 'humic' and 'Alberta') has been used informally for the material from Battle River (Forestburg) and Sheerness coalfields. Humalite is the weathered product of subbituminous coals and carbonaceous shales.

In Alberta commercial production occurred between 1957 and 1983, when Dresser industries (Magcobar) produced about 47,000 tonnes of humalite from their own pits and from a nearby coal mine in the Forestburg area. That material was used as a drilling fluid additive, but the operation closed due to the decline of oilfield drilling activity.

While the traditional oilfield markets for humic acid products shrank in North America, new opportunities were opening up in agriculture, horticulture and reclamation. Research since the mid 1960s has demonstrated that humic acids are effective as soil conditioners, especially in saline and alkaline soils, and in soils that are depleted in organic matter. They also appear to be effective against certain types of soil contamination.

We estimate the value of humic acid products currently being sold in Alberta to be under $500,000 for agriculture/horticulture/environmental applications and about $140,000 for oilfield applications. Alberta's known speculative resources are upward of 2 million tonnes. Indicated resources are about 272,000 tonnes and measured resources are about 118,000 tonnes.

We estimate that humalite could be processed and sold in Alberta for less than $62.00/tonne or about 30 ¢/kg which is less than half the current cost of imported products. Given the extensive agricultural activities in Alberta and the growing need for reclamation (about 200 hectares of mining lands and 1,500 hectares of well sites are being reclaimed annually in Alberta), humalite could capture a market of 45,000 tonnes per year or more.

Place Keywords

Hoffman, G.L., Nikols, D.J., Stuhec, S. and Wilson, R.A. (1993): Evaluation of leonardite (humalite) resources of Alberta; Alberta Research Council, ARC/AGS Open File Report 1993-18, 48 p.