DNR Report 358; 2003; Inventory of Publicly Owned Stockpiles and Natural Aggregate Resources at the Former LTV Mine and Vicinity

Executive Summary extracted from page v of report 358, 2003:

EXECUTIVE SUMMARY LTV Steel Mining Company mined magnetic taconite from the eastern end of the Mesabi Range in northeastern Minnesota for more than 40 years. During that time, LTV stockpiled on the order of a hundred million tons of waste rock and low-grade ore rock. Prior to that, previous companies mined natural iron ore and stockpiled various materials during those operations.

LTV filed for bankruptcy and closed the mine on January 5th, 2001. Cliffs Erie LLC, a subsidiary of Cleveland Cliffs, Inc, purchased the mining property and associated assets, including the railroad. Currently, mining does not occur on the property, and Cliffs Erie manages ongoing reclamation obligations and actively pursues economic and development opportunities of the property.

 

 

An opportunity now exists where the existing infrastructure and vast resources of broken rock could be used to supply demands for crushed rock aggregate, rip rap, railroad ballast, and decorative stone. The existing infrastructure at the former LTV Mine—electrical power, loading pockets, and rail lines--is conducive to establishing a high-volume operation.

The purpose of this project was to inventory the publicly owned rock and overburden stockpiles and explore for natural deposits of aggregate created by glacial activities in the evaluation area. A chief component of the inventory was to photograph each rock stockpile. The 103-square-mile evaluation area covers the former LTV mine and surrounding lands in St. Louis County, MN. Within Ranges 14 and 15 West, the area includes portions of Township 58N, all of 59N, and portions of 60N.

The results of this project include this report, one Plate that shows current infrastructure, and a second Plate that shows the locations of and kinds of stockpiles, occurrences of natural aggregate and abundant natural boulders, data collection sites, photo sites, and public land ownership. Also included are digital photos, a database, and rock samples reserved for review by interested parties.

All the stockpile materials were placed into five major categories: 1) lean taconite, 2) waste rock, 3) overburden, 4) lean ore, and 5) taconite. When LTV actively mined, the rock that was not processed was separated into these categories based on magnetic iron content. Rock that had between 10 and 19% magnetic iron was placed on lean taconite stockpiles, and rock with less than 10% magnetic iron was placed on waste rock stockpiles. The lean ore and taconite stockpiles are associated with natural ore mining.

Alternative uses of the stockpiled materials such as crushed rock aggregate, large and small rip rap, railroad ballast, and decorative stone are suggested. Some of the rock stockpiles contain materials that have potential for decorative stone with interesting patterns and colors. Four major classifications based on color were developed for the rock stockpiles. These were 1) gray with subtle color bands, 2) dark brownish gray, 3) gray with brown bands, and 4) mixed assortment of pale green, reddish purple, brown with thin light brown laminations, and gray rocks. Color classifications 1 and 3 are mostly associated with lean ore stockpiles, and classifications 2 and 4 are mostly associated with waste rock stockpiles. The stockpiles were not built based on rock colors, but iron content, so the color usually varies within any given stockpile.

Some rock and overburden stockpiles around the Embarrass Natural Ore Pit (sections 5 and 6, T. 58N, R. 15W) have potential for decorative stone or gravel.

Natural gravel was found in most of the evaluation area except in the northeast. Except for scattered areas south of the mine pits where the gravel contains significant quantities of argillite, it appears to be of good quality. Concentrations of natural boulders occurred mostly along the Giants Range in the western part of the evaluation area. The potential for quarrying granite for crushed rock aggregate exists in certain areas.

 

View or download report

Report 358: Inventory of Publicly Owned Stockpiles and Natural Aggregate Resources at the Former LTV Mine and Vicinity
(20 pages, 8.5 x 11 inches, 807 KB)
Author: G.D. Melchert

Report 358: Appendices
(30 pages, 8.5 x 11 inches, 1.6 MB)
Author: G.D. Melchert

Report 358: Photos; 10 pages of photos representative of the typical rocks found in the evaluation 
(10 pages, 8.5 x 11 inches, 200 KB)
Author: G.D. Melchert

Please note: Best results in viewing these reports and plates will be obtained by saving the files to a location of your choice and opening with Adobe Reader or Acrobat. Some report information may not display as a result of opening with Acrobat directly from a web browser.

 

View or download plates

Plate 1: Inventory of Publicly Owned Stockpiles and Natural Aggregate Resources at the Former LTV Mine and Vicinity
(44 x 34 inches, full size, Large File Size 14 MB)
Author: G.D. Melchert

Plate 2: Inventory of Publicly Owned Stockpiles and Natural Aggregate Resources at the Former LTV Mine and Vicinity
(44 x 34 inches, full size, 455 KB)
Author: G.D. Melchert

 

Download data

A zip file containing the database, photos, shapefiles, and spreadsheets produced for report 358 (zip file, Very Large File Size 63 MB).


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