Monammonium phosphate is black in color
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The ammonium phosphate produced by our factory has been turning black recently; the phosphoric acid itself is clear, but the finished product is black. We would appreciate it if everyone could help analyze this issue
Haha, we’ve encountered that too; it’s mainly due to the color of the ore – adjusting the ratio of the ores solves it
The dark color of monoammonium phosphate is mainly related to the color of the ore used in its production
Is the opinion from upstairs due to the MA produced by phosphoric acid? But phosphoric acid is clear and transparent; could it be that trace elements have formed colored solid impurities in an alkaline environment? We are keeping a close eye on this.
It is likely caused by changes in the impurities in the ore; also, pay attention to whether the operating conditions of the furnace are causing coal ash to be carried over to subsequent processes.
If it can be determined that a phosphate sediment is preferable, one can observe whether the concentrated slurry is white or black to determine whether the effect comes from the minerals or from the dry hot air.
In order to trial-produce powdered ammonium phosphate, the company first conducted experiments in the laboratory to determine the effect of different types of ore on the color of the resulting powdered ammonium phosphate. Through pilot tests and process trials, it was found that the color of the phosphate ore does not play a decisive role in the color of the ammonium phosphate; gray ore can also be used to produce white ammonium phosphate. The main reason for this is that impurities present in phosphoric acid cause side reactions during the neutralization process, due to the long duration of this reaction. This issue can be resolved by adjusting the composition of the ore mixture