This time last year in my review of the "other mining" sector, I quoted an analyst's report which said the share price of diversified junior mining house Metorex - then at 340c - could get as high as R12 over the next four years.

Instead, Metorex cracked the R12 barrier by the beginning of May this year. That sums up the boom in commodity prices: the "supercycle" defied every prediction of its demise and just kept on trucking.

The copper price, which had languished at US$0,8/lb in 2001, reached $1,50/lb by the middle of last year and then exploded to about $3,80 by early May. This surge pushed the Metorex share price hard, because the company has an operating mine in Zambia and is developing the major Ruashi-Etoile copper/cobalt project in the Democratic Republic of Congo (DRC).

Next came the price of zinc, the most laggardly of the major base metals over the past five years. Zinc was about 50c/lb from 2001 to May last year, then reached $1,70/lb a year later. Nickel did not perform as dramatically, but is still at sky-high levels. It moved up over the past year from $8/lb to $9,63/lb, after sitting at $2/lb in 2001.

Lead is so far the only metal to pull back from peak levels, and is trading at about $0,56/lb after hitting $0,65/lb in February. Lead sat at about $0,2/lb in 2001.

All of this created a marvellous business environment, in which diversified mining groups like Anglo American and BHP Billiton could thrive. The other big winner was Kumba Resources, which benefited from soaring iron prices - up 70% on delivery contracts to China's apparently insatiable steel mills.

China was the driving force in all of this, as in the past few years. Its rate of growth as it moves ahead with development and industrialisation programmes continues to defy predictions that it cannot continue. Instead, more commentators appear to be shifting to a view expressed two years ago by BHP Billiton CEO Chip Goodyear: China's development marks a major structural change in commodity markets and current demand levels are sustainable for at least a decade. Others, such as Investec Asset Management strategist Michael Power, also draw attention to the rise of India, another potential economic superpower.

Power believes that India lags behind China in development by about 12 years. Goodyear says that in terms of resource consumption, India is now where China was five years ago.

Put the two together and Power believes that "Chindia" will account for 45% of the world's total GDP by 2050. That will be more than the estimated combined total of the US at 26% and the EU at 15%. Power believes the bull market in commodities will run for another 10 to 20 years, as these two countries expand and India plays catch-up. If he's right, the big winners will be major diversified mining groups like Anglo, BHP Billiton and Rio Tinto. So far, BHP Billiton has largely outperformed Anglo because of its greater exposure to iron ore and its unique exposure - for a diversified mining group - to oil and gas. But Anglo has made up some lost ground, in particular since last November when it announced a group restructuring with guidelines for disposing of more noncore assets in order to concentrate on core mining.

BHP Billiton shares doubled over the 12 months to early May, reaching R140 from R71. Anglo beat that with a 116% rise in its share price, from R136 to R295.

Apart from the corporate restructuring, Anglo is making major changes in the running of the group. CEO Tony Trahar announced at the AGM on April 25 that he would be leaving within a year, while Anglo American SA CEO Lazarus Zim quit at the beginning of March.

Trahar will be leaving two years ahead of the normal Anglo retirement age of 60. Zim has quit after less than two years in his position. For Anglo, where executives being groomed for the top slots have traditionally been "lifers" wedded to the group, this is highly unusual.

It seems Zim wants to follow the route taken by Sam Jonah and set up businesses in Africa. Jonah stepped down from his executive responsibilities at AngloGold Ashanti just over a year ago. Since then he has become chairman of five junior mining companies in Africa.

Of course Zim stands to make vastly more money that way than in working solely for Anglo. But he will retain strong nonexecutive links with Anglo and will also be involved in structuring a BEE deal for Anglo Platinum.

The official reason for Trahar's departure is that he will have overseen the successful implementation of the first stage of Anglo's restructuring. Chairman Mark Moody-Stuart says: "It would be appropriate for him to make way for a new leader to oversee the next phase of our growth plans."

Speculation in the markets about the reasons for Trahar going include rifts between him and his top executives, and tensions with major UK financial institutions that wield substantial influence over what Anglo does.

Zim's major accomplishment before leaving Anglo was to complete the Kumba Resources BEE transaction, a milestone in the transformation of the mining industry. Insiders credit Zim as the real architect of this deal because of the way he won government support for the concept of a black-controlled, diversified mining house - which is what Kumba is about to become.

Anglo came out of this one smiling as well, because it achieved its ambition of controlling Kumba's iron ore business. This will be split off and listed as a separate operation in which Anglo will be the major shareholder.

Patrice Motsepe's ARM group (the former Avmin) saw a number of significant developments during the year. These included the link-up with Xstrata in the coal business and agreement with Assore over the future of ferro-alloy and iron ore subsidiary Assmang.

The two groups control Assmang outright, holding more than 95% of the stock. Assmang will be delisted this year as a result of the new agreement, reached after years of aggravation between Assore chairman Desmond Sacco and former Avmin CEO Rick Menell.

ARM is also now heavily involved in the push into the rest of Africa, following the successful listing of its exploration subsidiary Teal Resources on the Toronto stock exchange. Teal has projects in Zambia and the DRC.

There's big money to be made from resource projects in Africa, as political risk declines in a number of countries that were formerly no-go zones. Just ask any Metorex shareholder for confirmation.