Aggressive Sludge Treatment

Aggressive gold sludge: special pump technology delivers long service life without the addition of water

Global demand for gold and silver remains as high as ever. Precious metals are not only sought after by investors, but are indispensable materials in modern industry.       



However, mining these resources places machines under extreme stress and can increase the high price of the raw material. The sludge of crushed, gold-bearing stone that is transported for chemical extraction, for example, is extremely abrasive and can destroy pumping systems within a few days. Adding water does make it possible to convey the product, but also increases the effort required in the gold concentration process.  



In search of alternatives, a pump from another producer was installed in a mining region on a trial basis. However, the pump housing was completely destroyed within just two days. The high abrasiveness of the gold sludge was to blame. The stone particles in the sludge behave like sandpaper, particularly at high speeds, and wear away all surfaces extremely quickly – until the system fails completely.    



This effect can only be reduced by particularly smooth pumping at an economically viable volume, as further tests with a NEMO® progressing cavity pump demonstrated. To achieve a system with as long a service life as possible, despite heavy wear, the designers at NETZSCH selected tungsten carbide for the rotor. Tungsten carbide, with a scratch hardness of 9.5 on the Mohs scale, is almost as hard as diamond and is therefore scarcely affected by the grinding of the crushed stone. SBE, a nitrile material, was used for the stator. It is similarly extremely wear resistant, but also soft enough to prevent the points of contact with the rotor from wearing out too quickly. The progressing cavity pumps are also low power consumers and are easy to clean and maintain, which in turn reduces operating and maintenance costs. However, it is the durability of the pumps which is decisive when it comes to conveying gold. In the first test, the pump ran for three months without damage to the stator or rotor. The mine operator has since installed further three NEMO® pumps with an average service life of approximately 3.5 months. The service life exceeds the life cycle of earlier centrifugal pumps, which were completely worn out after three months, despite the addition of water.

Technical Data


在建筑材料行业内,需要输送的物质很多,从普通水到含有固体物料的高粘度腻子膏再到剪切敏感的泡沫材料等等。对 NEMO® 单螺杆泵而言,上述介质的输送问题简直就是小菜一碟——实际上,耐驰公司的专家们能够为您量身定制泵产品以满足您的个性化应用需求。

由于 NEMO 泵® 和 TORNADO® 工业转子泵能够实现各类介质的简便输送并具有高效精准的计量加药功能,因此,它们在该行业的应用范围十分广泛。



NEMO® SY 轴承直联自由轴伸设计用于工业领域

NEMO® SY 单螺杆泵在全球各个领域均能满足高标准应用。其轴承直联自由轴伸设计可使该泵在各种类型驱动装置下运行,如伺服电机、柴油发动机或液压驱动。

耐驰BY 直联型泵

NEMO® BY 单螺杆泵可用于各个行业,输送各种介质或进行高精计量。

NEMO® C.Pro®

NEMO®C.Pro® 计量加药泵是用于环保技术与化工行业,对各种化学品精确计量的合成型泵。其合成结构完全适合平稳与低脉动输送,并可对腐蚀性或非腐蚀性化学品进行计量。

TORNADO® Industrial Rotary Lobe Pumps T2

The TORNADO® rotary lobe pump is a positive displacement pump. The pumping action is generated by the contra-rotation of two rotors within the pump chamber which are synchronised externally. The media enters the pump chamber through the inlet port and is carried around the chamber by the rotors to the outlet port where it is discharged.