Some of the nation's biggest producers of coal are also among its biggest consumers -- steel companies and several large electric utilities.
Other producing companies are subsidiaries of the nation's oil companies.
Only a few of the big coal companies are coal producers pure and simple.
These differing circumstances have affected the companies points of view during the lengthy negotiations with the United Mine Workers union. The Carter administration is trying to exploit the differences, urging the steel companies to break with the others and settle with the union. But it may not suceed in dividing the mine owners because they also have a great deal in common.
Coal prices have risen sharply in the last five years, in part because of a sharp increase in oil and gas prices and in part because of sharply rising demand for coal.
Profits have followed prices, although they have declined somewhat during the last couple of years as labor costs have risen, labor productivity has declined and wildcat strikes and absenteeism continue to plaque many eastern mines.
Thus a major goal for all the soft coal operators is a contract that will test.
Thus a major goal for all the soft coal operators is a contract that will them a greater measure of labor stability.
One thing is clear to mine workers and mine operators alike: for the first time in decades they are fighting over an economic kitty that is large and growing larger.
Coal is no longer a fuel to be avoided. It has become the center-piece of President Carter's energy program to wean the United States off high-cost foreign oil. And even before the president launched his energy program last spring, electric utilities -- which consume 75 percent of all the coal produced in the United States -- began planning their new facilities around coal and started switching oil and gas facilities back to the fossil fuel.
While coal is dirty, hard to mine underground and pollutes the environment it is also plentiful and, despite its recent price rises, cheaper than either gas or oil.
The average utility paid $9 a ton for the coal it burned to generate electricity in 1973. Today it pays more than $19.
As a result, a coal company that made an average profit of 50 cents a ton in 1973 is making $2 a ton today, and made as much as $2.65 a ton in 1975, according to reliable government estimates.
The new UMW contract, when it is signed, will eat further into those profits.
Hard data on coal company profit margins is hard to come by, in large part because so few coal companies are independent producers anymore.
Peabody Coal Co. the largest, produced 70.5 million of last year's total 680 million tons. Peabody was owned by Kennecott Copper Corp. Last year the courts required Kennecott to sell Peabody to a consortium of about a half-dozen companies including construction and insurance firms.
Second-largest Consolidation Coal Co., which produced 55.9 million tons last year, is owned by Continental Oil Co., while Occidental Petroleum Corp. owns Island Creek Coal Co., the fourth biggest coal company.
Pittston Coal Co., the fifth biggest producer, is the largest independent coal company. United States Steel Corp. and Bethlehem Steel Corp. rank behind Pittston.
While large companies like Continental Oil and U.S. Steel own coal companies that are large in their own right, the coal industry is considered a "competitive" industry by most economists. No company controls more than 11 percent of total production and the four biggest control 25 percent. The top 20 firms control less than half the nation's coal output; 71 firms mine one million or more tons a year.
About 55 percent is mined above ground -- surface or strip mining --while 45 percent comes from below Earth's surface.
While most of the nation's coal is produced east of the Mississippi, a growing amount is being mined in the West.
Of the 680 million tons produced last year, utilities bought 475 million, steel companies used 77 million (mainly for coke), general industry consumed 68 million, 7 million went to retail customers and the rest was exported.