sand II

SAND MINING ECONOMICS
Both mineral and sand mining industries have been on the Michigan scene for over a century. Table 1 provides a further breakdown of the production and value of sand for industrial uses.

Table 1 - Production and use of industrial sand in Michigan in 1973

Uses of the sand	Production (tons)	Value ($)
Molding	4,466,000	10,402,000
Glass	535,000	2,018,000
Traction	295,000	710,000
Other (scouring powder, furnace sand, and hydrofacing sand)	433,000	1,087,000
Total	5,729,000	14,217,000

Historically and economically, those industries concerned with specific mineral utilization are located near a minable source of supply of that mineral. The foundry industry, which is dependent upon several mineral commodities, originally followed the coal or lumbering industry for its energy needs. Another consideration for bulk mineral users was proximity to cheap water transportation. Raw materials not found at the site could be imported by water at a better competitive price while at the same time a more economical way to ship bulky finished products was at hand. Limestone and clay for foundry use were often secured locally and brought in by truck or railroad.
As the foundry industry evolved over time, its associated technology placed more stringent requirements on the quality of sand used in its metal casting processes. Early foundry sands often were imported from southeastern Ohio. During the late 1910's and early 1920's, larger and larger quantities of dune sand began to be used in Michigan’s foundry industry as machines replaced manual labor and industrial expansion continued apace. New metal casting processes required a higher quality sand. At this time, it was found that some Michigan sands could not only withstand the extreme temperatures needed for pouring molten steel but were also more durable, cheaper to mine, and required little or no treatment prior to use in the casting process. Sand with these same characteristics is also preferred by the glassmaking and other minor sand dependent enterprises.

MINING, PROCESSING, AND RECLAMATION
Surface mining is the most common method of sand extraction. In this process, a front-end loader (see below) or crane with a clam shell (also below) is used to move sand . Sand is removed from the dune and loaded directly into a hopper where it is rough screened. After screening it is either loaded into trucks or onto conveyor belts and transported to a storage stockpile.
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The dredging method of sand mining (see below) is somewhat more costly and requires more elaborate equipment. The principle of this operation is to jet water under high pressure against the dune bank or pond bottom making a sand slurry. This slurry of riled sand is then sucked up by another pipeline and transported to a surge tank or storage pile. The water transporting the sand is recovered and returned to the pond. A dredge can mine sand to a depth of 20 m below the water surface.
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Source: J Lewis, Michigan Geological Survey Division Circular (#11), 1975

Hydraulic mining is very similar to dredging except the operation is conducted from a portable stand rather than from a dredge. Water is ejected under several hundred pounds pressure from a swivel nozzle which is mounted on the stand. The pressurized water stream is aimed at a dune bank, washing it down into a small holding pond (see below). From this point, the sand is pumped through a pipeline to a surge pile. Once the sand slurry reaches the surge pile, the water is drained off and recycled back through the high-pressure water line to be used again.
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Unlike sand, loosely cemented sandstone usually requires drilling and blasting before it can be mined. After overlying soil and unwanted rock have been removed holes are drilled and explosive charges are placed in them and detonated. The rock is broken into pieces that are small enough to be handled by front-end loaders. These pieces are loaded into trucks and transported to the plant for crushing and screening.

NEEDS OF THE SAND MINING INDUSTRY
Industrial quality sand must meet certain prescribed chemical and physical properties, must be located near its market, and must be mined, processed and shipped economically. From the industrial viewpoint, location of proven sand resources relatively near to market or to transportation facilities is second in importance only to the quality of the sand deposit. Because the sand must be transported to the market, transportation costs are an important economic factor. The heavy (sand) product needs to be transported at minimal cost. Long distance hauling cost is minimized by ship and rail transportation. Shorter haulage is usually provided by truck and is, hence, more expensive. In many cases, transportation charges are several times more costly than the value of the sand itself.
    In addition to location, sand must be available in sufficient quantities to assure its long-term availability to the industry. Availability of the resource must also be coupled with reasonable access to the resource itself. Public or private land ownership and local regulations, for example, all affect the industry’s capability of mining sand resources.
    Mining costs are another important consideration of the industry. The more expensive the extraction process the greater the cost that must be passed on to the consumer of the final product. Included in the cost of mining are blasting, removal of overlying rock and soil (overburden), mechanization, and reclamation of the mined area.
    The last major consideration of the sand mining industry is ore processing costs. Processing costs, like mining costs, must be kept as low as possible. The final product – industrial sand – must be nearly free from deleterious or undesirable minerals. Added treatment costs to remove unwanted material such as roots and rocks, increases the market price accordingly. Both the foundry and glassmaking industries must adhere to stringent physical and chemical sand specifications. Changes in processing techniques utilizing less desirable types of sand would require changes in technology with an attendant increase in cost.
    In terms of the industry’s economic impact, a 1975 newspaper article stated that there are 1,334 foundries employing 144,000 people that use sand from the Lake Michigan area. The foundry business, which depends upon sand for making cores and molds, is the one of the 20 largest industries in the USA, in terms of goods and services produced.
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SAND MINING AND THE ENVIRONMENT
The Lake Michigan Federation, a Muskegon-based environmental group, has been actively involved in the fight to save Michigan’s sand dunes for the past six years. In 1976 there were 15 active mining sites covering 3,228 acres. By 1999 that number had grown to 4,848 acres at 20 sites. About 46.5 million tons of sand have been removed since the passage of the dune protection act. The sand is used for making car molds, trains and airplane parts. The sand along the shore is useful to the auto industry because of its composition. It is unique in its purity. Quartz is the primary ingredient.
The depletion of the dunes also has negatively affected wildlife, such as the Piping Plover bird, which is on the federal endangered species list. Only 23 Piping Plover nests were accounted for in Michigan in 1996, many of which nest in the dunes.

CONCLUSIONS
Michigan’s industrial sand mining industry faces an uncertain future. This industry, like many other extractive industries, is being subjected to increasing public and governmental pressure to severely limit or stop its sand mining operations, especially along Lake Michigan’s shoreline areas.
    Dune sand is preferred by industrial consumers because of its chemical and physical properties, ready availability, and agreeable price. Sand mining operators prefer to quarry dune sand (below) because it is found in large volumes and is relatively free from excessive contamination and overburden. Compared to other sand sources it requires less processing, is more easily mined, and is close to bulk transportation facilities. The mining of thinner, inland sand deposits usually require additional processing, more handling, and disturbs large areas. The additional consumption of time and energy to carry out all of these operations contributes to increased costs.

    With the increased concern about sand mining in Michigan we are now forced to make a decision: 1) Should all dune sand mining be halted along the Great Lakes shorelands; 2) Should dune sand mining be allowed to continue unabated as in the past; or 3) Should we seek a compromise to these opposing positions?
    The elimination of sand mining within the Great Lakes shorelands, is supported by growing numbers of ecologically minded citizens. They contend that the dunes and their fragile ecosystems should not be destroyed as they are vital to the ecology of the area and invaluable educational and recreational assets that should be preserved intact for future generations to study and enjoy.
    The continuation of present mining practices is supported by equally concerned industrial opponents. They contend that Michigan is an industrial state and that industrial sand is the backbone of all basic industrial manufacturing in the state. Without dune sand our automotive and associated manufacturing industries would be forced to shut down or seek more costly alternatives.

Much of the text and imagery on this page is from a 1975 Michigan Geological Survey Division Circular (#11), by J. Lewis.

This material has been compiled for educational use only, and may not be reproduced without permission. One copy may be printed for personal use. Please contact Randall Schaetzl (soils@msu.edu) for more information or permissions.