Vale SA has a somber message for anyone betting on iron ore prices returning to the heady days of 2011.

The world’s biggest producer of the steel-making ingredient is prepared to unleash as much as 50 million metric tons of spare capacity to balance the market if prices get too high, Chief Executive Officer Fabio Schvartsman said.

High prices would lure inefficient producers back into the market and risk a repeat of past excesses that led to $1 trillion in value destruction, he said Wednesday in an interview with Bloomberg Television from the New York Stock Exchange, where Vale held its annual investor day.

“It was clear to see during the super-cycle, when in an unsustainable way companies made too much money and they didn’t know what to do with the money,” he said.

Schvartsman’s sense of market responsibility contrasts with the producer bravado of just a few years ago, when they battled for market share amid seemingly insatiable demand from Chinese mills. Now the industry catchphrases are value over volume and flight to quality.

As Vale shifts focus to high-grade deposits in northern Brazil’s Amazon region, it expects to produce 390 million tons next year and cap output at 400 million tons over the following four years, well below its 450 million-ton capacity.

China has been paying a premium nearly five times greater than what it was two years ago for high-quality ore, which helps mills there boost margins and comply with a government anti-pollution push.

Benchmark spot iron ore with 62 percent content fell 3.4 percent to $69.36 a dry ton on Wednesday, while 65 percent content material exported from Brazil lost 1.9 percent to $86.60 a ton, according to Metal Bulletin Ltd. On Thursday, futures in Singapore were steady, while the contract in Dalian dropped.

Vale expects across-the-board costs to drop significantly in the coming years as new mines ramp up. It has also been building capacity to house blended ores offshore, allowing it to maximize margins by mixing in lower-quality ore from its southern system.

Along those lines, Vale plans to lower the amount of ore it sells directly from its southern mines from a level of 41 percent in 2016 to 24 percent next year. High-grade production and blended ore will combine to account for 75 percent of sales volume in 2018.

With iron ore prices recovering from late-2015 lows, the company is generating the most cash since 2011 and is looking to cut its current debt load in half, to $10 billion, “in the shortest possible period,” Schvartsman said during the presentation.

By paying down debt quickly, Vale can attract a different breed of conservative investors, Till Moewes, a credit analyst with Schroders, said by telephone from New York. While his firm already holds Vale notes in some strategies, that position could “explode” if the company’s bonds are still trading at an attractive level, Moewes said.

Vale also expects to start trading on Brazil’s Novo Mercado—a segment of the exchange with higher standards of corporate governance—later this month, as it streamlines its ownership structure with a plan to end a 20-year shareholder pact with members that include state pension funds and development bank.

“We will become a boring company, a no-frills company, a company that will function and deliver like a clock,” Chief Financial Officer Luciano Siani Pires said.

In nickel, Schvartsman and his team are containing spending and trimming planned production in the next five years until prices recover further. The company continues to seek a partner for its New Caledonia operations to help fund a tailings dam.

In copper, the company is looking to grow.