Method for cullet quality grading
A method for grading the quality of cullet. Some embodiments include methods for generating a statistically significant sample of material from a collection of cullet contaminated with waste. Other embodiments include methods for evaluating various qualities of the sample with relatively simple techniques. Yet other embodiments include a uniform and reasonably simple method for communicating the results of the evaluation among different parties.
1. A method for evaluating cullet, comprising:
providing a quantity of cullet contaminated with other waste products;
removing a sample from the quantity of cullet;
counting the number of non-glass objects in the sample larger than a predetermined size;
associating a first numerical grade with the number;
separating from the sample one of amber cullet, green cullet, or flint cullet and determining a weight fraction of the separated cullet within the sample;
associating a second numerical grade with the weight fraction; and
evaluating the quantity of the cullet for use in a glass furnace using the first numerical grade and the second numerical grade.
2. The method of claim 1 which further comprises drying the sample and determining a fraction of weight lost by drying and associating a third numerical grade with the fraction of weight lost by drying, wherein said evaluating uses the third numerical grade.
3. The method of claim 1 which further comprises rinsing the sample and determining a fraction of weight lost by rinsing and associating a third numerical grade with the fraction of weight lost by rinsing, wherein said evaluating uses the third numerical grade.
4. The method of claim 1 which further comprises rinsing the sample and determining a fraction of weight lost by rinsing and associating the fraction of weight lost by rinsing with the weight loss by ignition, wherein said evaluating uses the weight loss by ignition.
5. The method of claim 1 which further comprises determining a weight percentage of cullet particles smaller than a predetermined size in the sample and associating a third numerical grade with the weight percentage of cullet particles smaller than the predetermined size, wherein said evaluating uses the third numerical grade.
6. The method of claim 5 which further comprises determining a weight percentage of cullet particles larger than a second predetermined size in the sample and associating the third numerical grade with the weight percentage of cullet particles smaller than the predetermined size and the weight percentage of cullet particles larger than the second predetermined size large size, wherein said evaluating uses the third numerical grade.