Coal Assay

Coal assay techniques are specific analytical methods designed to measure the particular physical and chemical properties of coals.

煤质分析技术是专门用来测量煤的特定物理和化学性质的特定分析方法。

These methods are used primarily to determine the suitability of coal for coking, power generation or for iron ore smelting in the manufacture of steel.

煤质分析主要用于确定炼焦、发电或炼钢过程中铁矿石冶炼用煤的适用性。

Chemical Properties of Coal

煤的化学性质

Coal comes in four main types or ranks: lignite or brown coal, bituminous coal or black coal, anthracite and graphite.

煤主要有四种类型：褐煤，烟煤，无烟煤和石墨。

Each type of coal has a certain set of physical parameters which are mostly controlled by moisture, volatile content (in terms of aliphatic or aromatic hydrocarbons) and carbon content.

每种类型的煤都有一组特定的物理参数，这些参数主要由水分，挥发分（就脂肪烃或芳族烃而言）和含碳量控制。

Moisture: Moisture is an important property of coal, as all coals are mined wet.

水分：水分是煤炭的重要属性，因为所有煤炭都是湿法开采的。

Groundwater and other extraneous moisture are known as adventitious moisture and are readily evaporated.

地下水和其他外来水分称为外在水分，很容易蒸发。

Moisture held within the coal itself is known as inherent moisture and is analysed.

煤中所含的水分称为内在水分，可以被定量分析。

Moisture may occur in four possible forms within coal.

煤中的水分有四种可能的形式。

• Surface moisture, water held on the surface of coal particles or macerals.

煤颗粒或其显微组分表面的水分。

• Hydroscopic moisture: water held by capillary action within the microfractures of the coal.

吸湿性水分：通过毛细作用保持在煤的微裂缝中的水分。

• Decomposition moisture: water held within the coal’s decomposed organic compounds.

分解水分：煤中分解的有机化合物中的水分。

• Mineral moisture, water which comprises part of the crystal structure of hydrous silicates such as clays.

矿物水分，是由含水硅酸盐（如粘土）的部分晶体结构组成的水。

Total moisture is analysed by loss of mass between an untreated sample and the sample once analysed.

总水分通过分析未处理样品和分析后样品之间的质量损失进行计算。

This is achieved by any of the following methods:

可通过以下任一方法实现：

• Heating the coal within a solution of toluene.

在甲苯溶液中加热煤

• Drying in a minimum free-space oven at 150°C within a nitrogen atmosphere.

氮气气氛下，在150°C的最小自由空间烘箱中干燥。

• Drying in air at 100~ 105°C and relative loss of mass determined.

在100~105°C的空气中干燥，并测定相对质量损失。

Methods 1 and 2 are suitable with low-rank coals but method 3 is only suitable for high-rank coals as free air drying low-rank coals may promote oxidation.

方法1和2适用于低变质程度煤，但方法3仅适用于高变质程度煤，因为自由空气干燥可能促进低变质程度煤的氧化。

Inherent moisture is analysed similarly, though it may be done in a vacuum.

固有水分的分析类似，但是它需要在真空中进行。

Volatile Matter: Volatile matter in coal is the components of coal, except for moisture, which is liberated at high temperature in the absence of air.

挥发分：煤中的挥发分是煤的组成部分，水分除外，水分在没有空气的情况下在高温下释放出来。

This is usually a mixture of short and long chain hydrocarbons, aromatic hydrocarbons and some sulphur.

挥发分通常是短链和长链烃、芳香烃和一些硫的混合物。

The volatile matter of coal is determined under rigidly controlled standards.

煤的挥发分是在严格控制的标准下测定的。

In Australian and British laboratories this involves heating the coal sample to (900±5) °C for 7 minutes in a cylindrical silica crucible in a muffle furnace.

在澳大利亚和英国的实验室中，在马弗炉中的圆柱形二氧化硅坩埚中将煤样加热至（900±5）°C 保持7分钟。

American Standard procedures involve heating to (950± 25) °C in a vertical platinum crucible.

美国标准步骤是在立式铂坩埚中将煤样加热至（950±25）°C。

These two methods give different results and thus the method used must be stated.

由于这两种方法得出的结果不同，因此测定挥发分必须说明所使用的方法。