 The colonial state needed to be able to levy taxes in money on the Congolese, so it was important that they could make money by selling their produce or their labour within the framework of the colonial economy.The economic boom of the 1920s turned the Belgian Congo into one of the leading copper-ore producers worldwide.In 1926 alone, the Union Minière exported more than 80,000 tons of copper ore, a large part of it for processing in Hoboken (Belgium).