The Major Ore Clusters of Super-Large Iron Deposits in the World, Present Situation of Iron Resources in China, and Prospect

The metamorphosed sedimentary type of iron deposits（BIF） is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Carajas in Brazil, Hamersley in Australia, Kursk in Russia, Central Province of India and Anshan-Benxi in China. Subordinated types of iron deposits are magmatic, volcanic-hosted and sedimentary ones. This paper briefly introduces the geological characteristics of major super-large iron ore clusters in the world. The proven reserves of iron ores in China are relatively abundant, but they are mainly low-grade ores. Moreover, a considerate part of iron ores are difficult to utilize for their difficult ore dressing, deep burial or other reasons. Iron ore deposits are relatively concentrated in 11 metallogenic provinces（belts）, such as the Anshan-Benxi, eastern Hebei, Xichang-Central Yunnan Province and middle-lower reaches of Yangtze River. The main minerogenetic epoches vary widely from the Archean to Quaternary, and are mainly the Late Archean to Middle Proterozoic, Variscan, and Yanshanian periods. The main 7 genetic types of iron deposits in China are metamorphosed sedimentary type（BIF）, magmatic type, volcanic-hosted type, skarn type, hydrothermal type, sedimentary type and weathered leaching type. The iron-rich ores occur predominantly in the skarn and marine volcanic-hosted iron deposits, locally in the metamorphosed sedimentary type（BIF） as hydrothermal reformation products. The theory of minerogenetic series of mineral deposits and minerogenic models has applied in investigation and prospecting of iron ore deposits. A combination of deep analyses of aeromagnetic anomalies and geomagnetic anomalies, with gravity anomalies are an effective method to seeking large and deep-buried iron deposits. China has a relatively great oresearching potential of iron ores, especially for metamorphosed sedimentary, skarn, and marine volcanic-hosted iron deposits. For the lower guarantee degree of iron and steel industry, China should give a trading and open the foreign mining markets.

China＇s Graphite Resources and the Supply-Demand Situation

Graphite is a rare and important nonmetallic mineral. Till 2017, the global graphite resource reserves had exceeded one billion tons, which are mainly distributed in China （0.45 billion tons）, Mozambique （0.14 billion tons）, Madagascar （0.1 billion tons）, Turkey （0.09 billion tons）, Brazil （0.07 billion tons）, and Tanzania （0.07 billion tons）. These six countries include about 92% of the global graphite resource reserves, of which China accounts for about 45% of the world＇s total resource reserves.

Integrated water resources management for emergency situations： A case study of Macao

Integrated urban water management （IUWM） is a useful tool that can be used to alleviate water resource shortages in developing regions like Macao, where 98% of the raw water comes from China's Mainland. In Macao, scarce water resources deteriorate rapidly in emergency situations, such as accidental chemical spills upstream of the supply reservoir or salty tides. During these times, only the water from the two freshwater reservoirs in Macao can be used. In this study, we developed urban water management optimization models that integrated the raw water supply from the two reservoirs with various proposed governmental policies （wastewater reuse, rainwater collection, and water saving）. We then determined how various water resource strategies would influence the urban water supply in Macao in emergency situations. Our results showed that, without imported raw water, the water supply from only the two Macao reservoirs would last for 7.95 days. However, when all the government policies were included in the model, the supply could be extended to 13.79 days. Out of the three non-conventional water resources, wastewater reuse is the most beneficial for increasing the Macao water supply, and rainwater collection also has great potential.