There are three types of potassium chloride products: I am a special industrial use of potassium chloride, which is suitable for electrolysis of potassium hydroxide, potassium chlorate, and other industrial use of potassium chloride Π, suitable for a variety of potassium fertilizer production and chemical industry. Class III agriculture uses potassium chloride, which is suitable for the application of compound fertilizer or directly as fertilizer.

　　本文所述的氯化钾适用于复合肥或直接用作肥料。它以白色或红色晶体的形式存在，其主要成分为氧化钾。氯化钾产品氧化钾含量检测时，应注意以下几个方面:

　　The potassium chloride described in this paper is suitable for compound fertilizer or directly used as fertilizer. It exists in the form of white or red crystal, and its main component is potassium oxide. In the detection of potassium oxide content of potassium chloride products, attention should be paid to the following aspects:

　　温度控制是配制溶液的首要条件

　　Temperature control is the primary condition of solution preparation

　　根据GB/T 6678-2003《化工产品通用抽样规则》6.6的规定，在试验中应确定样品的抽样单位数量。采样器从袋口的一角取样品袋深的3/4处，将采集到的样品均匀混合，用四分法将其还原为待测样品量。由于氯化钾肥料具有很强的吸水性，在制备样品时应尽快进行。样品制备后，称量5g样品，取0.001g精度，加入150ml水。然后，样品在不断搅拌下加热，略煮5分钟。冷却20℃后，将样品转移到500ml的容量瓶中。这是一个关键的环节。为了方便一些巡视员，他们并没有在水温达到20℃时设置音量，但是当水温达到20℃时，结果却很高。当水温低于20℃时，结果很低。两个恒定体积导致两个误差。因此，准确的测试温度是测试结果准确性的关键。将水温高于20℃时的试验结果与水温为20℃时的试验结果进行对比，如表1所示。

　　According to 6.6 of general sampling rules for chemical products (GB / T 6678-2003), the number of sampling units shall be determined in the test. The sampler takes samples from one corner of the bag mouth to 3 / 4 of the bag depth, evenly mixes the collected samples, and reduces them to the sample quantity to be measured by quartering method. Because potassium chloride fertilizer has strong water absorption, it should be carried out as soon as possible when preparing samples. After sample preparation, weigh 5g sample, take 0.001g precision, add 150ml water. Then, the sample is heated under constant stirring and boiled for 5 minutes. After cooling to 20 ℃, transfer the sample to a 500 ml volumetric flask. This is a key link. For the convenience of some inspectors, they did not set the volume when the water temperature reached 20 ℃, but when the water temperature reached 20 ℃, the result was very high. When the water temperature is below 20 ℃, the result is very low. Two constant volumes result in two errors. Therefore, accurate test temperature is the key to the accuracy of test results. Compare the test results when the water temperature is higher than 20 ℃ with the test results when the water temperature is 20 ℃, as shown in Table 1.

　　洗涤剂和蒸馏水对试验结果的影响

　　Influence of detergent and distilled water on test results

　　氧化钾含量的测定方法与iso2051:1976《氯化钾的测定-工业用钾含量-四苯基硼酸钾的重量法》相同。在弱碱性介质中，四苯基硼钠[NaB(C6H5)4]碱性溶液和洗涤液直接影响试验结果。由于制备的四苯基硼钠很不稳定，容易产生浑浊。如使用前发现浑浊，应先用中速滤纸过滤，否则测试结果过高。洗涤液和蒸馏水的效果也不同。有些检验员认为配制洗涤液，用蒸馏水代替洗涤液比较麻烦，检测结果会比较低。蒸馏水的原始结果与洗涤剂的正确结果的比较如表1所示。

　　The determination method of potassium oxide content is the same as iso2051:1976 determination of potassium chloride content of potassium for industrial use weight method of potassium tetraphenylborate. In the weak alkaline medium, the alkaline solution and washing solution of sodium tetraphenylborate (NAB (C6H5) 4) directly affect the test results. Because the preparation of sodium tetraphenylboron is very unstable, it is easy to produce turbidity. If turbidity is found before use, filter with medium speed filter paper first, otherwise the test result is too high. Washing liquid and distilled water have different effects. Some inspectors think that it is troublesome to replace the detergent with distilled water when preparing the detergent, and the test results will be relatively low. The comparison between the original results of distilled water and the correct results of detergent is shown in Table 1.

　　洗涤步骤是关键

　　Washing step is the key

　　试验中，试验液过滤后的洗涤步骤存在洗涤终点不清的问题。根据GB 6549-1996氯化钾的规定，先提取上清液过滤，再用洗涤液(即氯化钾溶液)将沉淀转移到过滤器中。，室温饱和四苯基硼钾溶液)。上述洗涤液继续洗涤沉淀约12次，每次洗涤约5ml洗涤液。如果检查人员没有清洗足够的次数，在干燥的坩埚上可以清楚地看到粉红色物质，这是未清洗的氢氧化钠和酚酞产生的物质的颜色，终会导致高钾含量。因此，洗涤次数不应少于12次。将洗涤次数少于12次的原始结果与不少于12次的正确结果进行比较，如表1所示。

　　In the test, there is a problem that the end-point of washing is not clear after the test solution is filtered. According to the provisions of potassium chloride in GB 6549-1996, the supernatant is extracted and filtered first, and then the precipitate is transferred to the filter with the washing solution (i.e. potassium chloride solution). , room temperature saturated potassium tetraphenylboron solution). The above washing solution is washed and precipitated for about 12 times, and each time about 5ml of washing solution is washed. If the inspector does not clean enough times, the pink material can be clearly seen on the dry crucible, which is the color of the material produced by the uncleaned sodium hydroxide and phenolphthalein, which will eventually lead to high potassium content. Therefore, the washing time should not be less than 12 times. Compare the original result of less than 12 times of washing with the correct result of no less than 12 times, as shown in Table 1.

　　结论

　　conclusion

　　综上所述，在对以氧化钾为主的氯化钾产品的检测中，应充分注意几个关键环节，避免和克服各种可能引起误差的因素，以保证检测结果的准确性。

　　In conclusion, in the detection of potassium chloride products mainly composed of potassium oxide, several key links should be paid full attention to to avoid and overcome various factors that may cause errors, so as to ensure the accuracy of the detection results.