| By then several boracic fluxes had been developed for assaying metal ores. |
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| The sintering process is a pre-treatment step in the production of iron where fine particles of metal ores are agglomerated by combustion. |
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| Peat extraction, quarries and open-cast mining, and processing of metal ores or coal. |
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| Later, folding and faulting happened when the earth built mountains, raising the deposits of metal ores high above sea level. |
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| Wales has also had a significant history of mining for slate, gold and various metal ores. |
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| European industrialists sought raw materials such as dyes, cotton, vegetable oils, and metal ores from overseas. |
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| The need for metal ores stimulated trade, as many of the areas of early human settlement were lacking in ores. |
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| The power of a wave of water released from a tank was used for extraction of metal ores in a method known as hushing. |
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| Secondary types of activity included the extraction of ferrous metal ores, production of half-finished products and the production of metal structures. |
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| The chief natural resources of the region, undoubtedly playing a crucial role in Etruscan commerce and urban development, were the rich deposits of metal ores found in both northern and southern Etruria. |
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| The field also magnetizes the crust, and magnetic anomalies can be used to search for deposits of metal ores. |
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| His work describes the highly developed and complex processes of mining metal ores, metal extraction and metallurgy of the time. |
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| The Heads of the Valleys towns, including Rhymney, Tredegar and Ebbw Vale, rose out of the industrial revolution, producing coal, metal ores and later steel. |
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