ABSTRACT 

The aim of the thesis is a technical evaluating of a new proposed clarification method at low retention time for production of high quality raw sugar. The new proposed method depends on using double stage froth flotation for clarification of mixed juice as competitive method of the conventional one utilizing from nearly the same principle adopted in clarification of sugar melt by phosphatitation flotation method.

The thesis contains four chapters as follows: introduction, literature review, experimental work, and results and discussion.

 Experiments were carried out at the pilot plant for sugar research in quos sugar factory using fresh mixed juice on a batch semi industrial level.

Good Results Were Obtained Such As :

1.  Application of double stage froth flotation for production of high quality raw sugar has been succeeded.

2.  Using sulphitation in combination with double stage froth flotation was led to produce a clear juice suitable for the production of white sugar with high grade. 

3. The retention time each stage of froth flotation is only 20 minutes thus the volume of clarifier will be reduced to half the volume of existing one in case of using double stage froth flotation. However, the clarifier volume will be lower than the volume of multi tray clarifier by 1/6 in case of using one stage froth flotation. 

4. Results of the experiments showed that the properties of clear juice from the first stage of froth flotation had to large extent the same one of clear juice from turbidity from the clear juice. Thus, this will be reflected to the quality of the produced sugar and its yield. 

5. The scum resulted from the new proposed method is lower than the mud obtained from the conventional method by about 60%. This means that the cost of sugar recovery from the scum will be less. 

At The End Of Thesis, It Was Recommended To test the new method on a semi industrial scale of automated continuous operation so that a model for large industrial scale can be designed and the economical evaluation can be achieved.