"We have come here to follow the history of our fathers because there is employment here."

Reuben Kuna was explaining why for the past 34 years he has left his family in Mozambique for 16 months at a time and come to work as one of this country's 500,000 black gold miners. He is part of a work force of major importance to South Africa, which supplies 72 percent of the noncommunist world's gold.

Kuna and his fellow black miners make up two-thirds of South Africa's mining labor force. That force hauled 67 million tons of ore from the country's 44 gold mines through last September. Smelted down to 506 tons of gold, it was sold at record prices, bringing the government in Pretoria close to $4 billion in eight months.

In the last few years South Africa's mining industry has found itself confronted with a better educated, more demamding work force at the same time that modernization and mechanization have underlined the need for a more skilled, stable and loyal staff -- something not produced by the high turnover typical of the migrant system.

In addition, the political thrust os the country's industrial relations now endorsed by both the government and private enterprise aims at creating a prosperous and unrevolutionary work force, which in effect mandates a change in the old ways of dealilng with black labor.

It is considered especially important for South Africa to implement these changes if it is to maintain its role as a reliable producer of strategic materials for exports to the West.

The higher gold price since 1972, according to Harry Oppenheimer, chairman of the large Anglo-American mining conglomerate, also had made it "possible and practical to do things that could not have been contemplated before."

Forces promoting change in a 90-year-old industry were given added impetus by events in the past decade. From 1973 to 1975 there was serious unrest and violence in the mines during which 132 men were killed and at least 500 injured, some by police, others by fighting among miners.

In 1974 the Malawian government temporarily stopped all recruitment. There for mine labor after a plane carrying Malawian miners home crashed, killing all aboard. In the same year, the approach of black rule in Mozambique led to a decline in the number of miners from that country.

Realizing the vulnerability of importing labor from seven nearby countries, the mining industry sought to attract more South African blacks by making mining more appealing. Today, South African blacks acount for 54 percent of the half million-strong black mining force. Eight years ago, they were only 25 percent.

In the 1970s, black gold miners' wages rose by more than 800 percent and the black-white wage ratio narrowed from 21 to 1 in 1970 to 7 to 1 in 1980.

Family housing for the top echelon ov black workers is also being provided in the belief that "it would be a good thing to have more blacks living on the mine -- they would be more contented and probably stay with us forever," according to Henry Slater, manager of Randfontein gold mines, where an attractive compound of 187 houses is under construction.

In addition, the companies upgraded the barracks that house the migrants, improved the food and provided literacy classes and sports facilities. Some offer express bus services home on weekends, and others have lodgings for wives.

Industrial relations departments were set up to improve race relations and halt abuse of, and assaults on, blacks by white supervisors. "Liaison committees" sought to improve communication with workers.

Some managers are uneasy eith these committees, because "we don't believe it is industry's job to go out and form unions," according to Johan Liebengerg, an industrial relations expert. He added that the managers "look forward to the day" when multi-racial unions are formed so they would not have to negotiate "with two competing unions in a polarizing situation."

Under pressure from the government and companies, six of the eight all-white unions connected with the mining industry have reluctantly taken tentative steps toward accepting black members or creating a "parallel" black branch.

The most crucial holdout is the predominantly Afrikaner Mine Workers'Union led by Arrie Paulus, who publicly refers to blacks as "baboons" and who accuses Labor Minister Fanie Botha of having "sold out" white interests.

Paulus' union refuses to allow blacks to get the crucial "blasting certificate" that is now blocking black advancement underground in the mines and is the last statutory job reservation of consequence on the books. This means that white blasters are getting at minimum $900 a month while a black team leader, who often does the work of the blaster, can get only about $650.

Black miners also complain that "as soon as you have got blacks who know how to do things, instead of promoting him, they downgrade the job and pay them less." They also sense the resentment among white miners.

"Now we have personnel and industrial-relations departments. The white men hate these departments, the don't like it that a black can lay charges" if one is assaulted, said a miner from Transkei.

Other miners say the liaison committtees lack teeth.

"The management only wants to discuss things they want to discuss," said one miner who recently resigned from a committee. But he conceded that there is no migrant work force that is only 40 percent literate.

The improvements fail to change the basic condition -- the migrant life -- that is the greatest concern of the miners.

"Compound life is unbearable because we don't normally mix with the other sex," said Tota, a miner from Lesotho. The worst thing for him, he said, is "staying away from my family. My wife is very sorry. She had illegitimate children while I was gone. She is in need of enjoying herself."

"Many of our men take up sodomy and drinking, they are the two big problems," he added.

Asked if he felt important to the mines, Tota replied, "We blacks, when we are discharged, even if it is not our fault by the time you get a train there would be nine guys ready to do your job. So I'm not important."