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1.
The reduction and the smoothened amplitudes of the chloride concentrations since 2000 have resulted in a gradual positive development of the aquatic fauna in the River Werra. In the salinized section of the river increasing species numbers have been determined along the salinity gradient, which shows maximum chloride concentrations of about 2500 mg/l, maximum potash concentrations at approximately 200 mg/l, and magnesia concentrations peaked at 320 mg/l. As an immediate consequence of the reduction in salt concentration the immigration of various caddis fly species into the lower River Werra was observed. The Number of taxa per sample rose from 5 to more than 30 in the lower Werra region. Changes in species-richness could be seen more frequently in river sections where chloride concentrations fluctuated around 1500 mg/l. 相似文献
2.
S. K. P. Coles C. I. Wright D. A. Sinclair P. Van den Bossche 《Marine Georesources & Geotechnology》2002,20(2):87-110
Extensive potassium and phosphorous-rich mineralization occurs on the outer continental shelf of the southern and west coasts of South Africa and Nambia. This article reviews the potential of exploiting these deposits in an environmentally sound manner for the manufacture of fertilizer. At present, reserves of potash and phosphate fertilizer are exploited from terresterial deposits, the majority being surface mined. The use of fertilizer in South Africa has shown no growth in the past 13 years, and, in some years, usage has even declined. On average, over the last decade, South Africa has consumed 2 million Mt of fertilizer (including nitrogen) per annum, the vast majority of phosphate fertilizer being produced by FOSKOR from the Phalaborwa Igneous Complex. Potash fertilizer is imported into South Africa. Although fertilizer consumption is expected to decrease in the short-term, there are good future prospects for the domestic and international fertilizer market. Considerable research into both glauconitic (containing K 2 O) and phosphatic deposits along the southern African continental shelf indicate that these sedimentary deposits have a complex genesis and mineralization. Of the total K 2 O reserves of 1300 million Mt on the southern African margin, 1000 million Mt is located off the southern African west coast, and the remainder situated on the Agulhas Bank. The largest glauconite concentration ( ±300 million Mt K 2 O) off southern Africa lies west of Saldanha Bay, South Africa. The distribution of P 2 O 5 off southern Africa is dominated by the vast deposit between Walvis Bay and Luderitz, Nambia. This reserve is estimated to contain 1000 million Mt of greater than 5% P 2 O 5 in a relatively small area of about 10000 km2. The phosphorite deposit south of Saldanha Bay constitutes a reserve of ±3500 million Mt of apatite and the deposit on the Agulhas Bank comprises 5500 million Mt. The phosphate deposit off Saldanha Bay occurs as an extensive, low to medium grade deposit. Although vast resources of potash and phosphatic minerals occur along the southern African outer continental shelf the expensive nature of marine exploitation may render most of these deposits, especially the phosphates, subeconomic. The low price of fertilizer andextensive natureontheonland deposits, although confined to asmallnumber of countries, mean that it will not be financially viable to extract these deposits. Assuming high grade glauconitic sand with the right composition can be located, the high market price indicates good future prospects for these potash deposits. 相似文献
3.
我国是缺钾大国,探明的可溶性钾盐十分有限,柴达木盆地是我国盐湖钾盐的聚集地,含水层骨架中含有数亿吨低品位固体钾矿,开发出这些低品位固体钾盐对增加国内钾肥供给,保障粮食安全具有重大意义。青海盐湖工业股份有限公司历经十年开发出低品位固体钾盐的浸泡式溶解转化方法,试验表明,固体钾盐的溶解转化率随固体钾品位的增加而增加,累计溶解转化率为56%～98%。该技术在柴达木多个盐湖得到推广应用,察尔汗盐湖保有固体钾盐达2.96×10~8 t,平均品位KCl为1.24%,根据试验数据回归分析溶解转化率77%,可溶解转化出钾盐(KCl)约2.28×10~8 t,柴达木盆地盐湖保有3.43×10~8 t固体钾盐,平均品位KCl为1.25%,溶解转化率78%,可溶解转化出钾盐(KCl)2.68×10~8 t,大幅度增加了钾盐储备量。 相似文献
4.
5.
对近年来国内外盐湖资源开发利用的进展情况加以介绍 ,也涉及到国外钾、锂、镁、硼、碘等相关产品的生产、消费、价格等情况。还对资源开发的可持续发展以及我国盐湖及相关资源开发的某些问题加以讨论。 相似文献
6.
通过钾盐矿床与晶间卤水分异特征及成因的分析对比，认为晶间卤水分异的过程也就是钾盐矿床形成的过程。胶结浸染状固体矿形成于晶间卤水分异初期的浓缩阶段，改造于分异后期的淡化阶段；晶间卤水矿和层状固体矿形成于淡化阶段。 相似文献
7.
我国钾盐资源的开发利用 总被引：12，自引：3，他引：12
本文以基础统计资料为主，首先叙述了我国钾盐资源的基本情况及其分布特点和勘查程度，介绍国内钾资源开发利用的现状，就如何开发利用我国钾资源，解决国内钾肥短缺问题提出了一些建议． 相似文献
8.
Potash salt is one of key scarce strategic resources. Searching for large scale of potash salt deposit is one big problerm which Chinese academic community faces. Many new discoveries of world potash deposit have been made in recent ten years, which provide abundant practical information and complement the potash metallogenic theory. Through the summary of the potash forming characteristics at home and abroad, the paper studies the potash forming time, tectonic condition, paleogeographic condition, paleoclimate, basin location and salt source. Potash is mainly formed in Permian, Cretaceous, late Jurassic, Cambrian and Devonian. The combination of structure and environment helps to form large scale of evaporation. The climate cycle is related with crust activity. As the other ore deposit, the formation of potash ore also needs dry climate. Potash is the product of final stage in brine evolution, and therefore, it needs persistent drought climate. However, the climate condition is very complicated. Drought climate belt also occurs in humid climate stage, which is controlled by geomorphology. Potash ore can also form in local drought condition. Generally, potash forms in rock salt basin. However, the actual situation is very complicated. Some potash basin is coincided with rock salt basin, some is on one side of rock salt basin; and some are even in the outside of rock salt basin. Salt materials can be from three sources: marine source, terrigenous source and deep source.The paper gives an overview of the research status about the potash deposit forming conditions, which has great guiding significance for searching potash deposit in China. The paper also summarizes the three types of metallogenic models for potash deposit, including epicontinental metallogenic model, abnormal marine evaporation model and rift valley model. The three models are mainly different in material sources, in which the potash in epicontinental metallogenic model is from seawater; the potash in abnormal evaporation model is from nonmarine brine and the potash in rift valley model is mainly from deep material of volcanic activity. 相似文献
9.
Potash in a salt mushroom at Hormoz Island, Hormoz Strait, Iran 总被引：2，自引：0，他引：2
Increasing volumes of potash are currently being discovered in a cluster of diapirs of Hormoz (formerly Hormuz) salt near Bandar Abbas, Iran. Most of the potash beds studied so far occur in complex recumbent folds in a salt mountain that would be difficult to exploit safely. However, Holocene marine erosion removed any salt mountains from a sub-group of near-shore Zagros diapirs and exposed their deeper structural levels. Even though these diapirs are still active, their potash deposits are likely more tractable to safe exploitation than in a salt mountain — as we make clear here for Hormoz Island.Geochemical surveys on Hormoz Island reveal two separate potash anomalies that are valuable pseudo-stratigraphic markers. Integrating field measurements of the attitudes of bedding with lineaments on air photos suggests that Hormoz Island consists of a mature bell- or plume-shaped mushroom diapir with potash beds wound around a toroidal axis of rotation near current exposure levels.2D numerical models simulate the salt mushroom on Hormoz Island and its internal circulation. They also suggest that the diapir has a wide overhand above a narrow stem in this gas-rich region. We use the mushroom diapir model to outline a regional exploration strategy that has the potential of influencing the world potash market thereafter. 相似文献
10.