用沉降法制备乳剂的优点是众所周知的,然而影响乳剂性能的因素还很多。例如,沉降剂的选择,沉降物的形状,水洗水质量、水洗工艺以及复溶条件等等。在实际操作过程中尤其是乳剂沉降物的水洗工艺,除了影响乳剂的照相性能外,若操作不妥,还会失银。因此,应引起人们的重视。目前人们常用的水洗方法有三种。其一是乳剂沉降物用水浸泡二至三次,以达到水洗目的。其二是采用含酸的水洗水(即1升水洗水中加入1毫升10％醋酸)。其三是采 The advantages of using the sedimentation method to prepare emulsions are well known, but there are still many other factors that affect the performance of the emulsion. For example, the choice of settling agent, the shape of the sediment, the quality of washing water, washing process and the conditions of reconstitution and so on. In practice, especially the process of washing the emulsion sediment, in addition to affecting the photographic properties of the emulsion, if not properly handled, but also loss of silver. Therefore, it should cause people’s attention. Currently there are three commonly used methods of washing water. One is the emulsion sediment soaked in water two to three times, in order to achieve the purpose of washing. The second is the use of acid-containing washing water (ie, 1 liter of water washing added 1 ml of 10% acetic acid). The third is mining