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 pile of cullet contaminated with other waste products;
taking a pilot sample from each of a plurality of predetermined circumferential locations around the pile;
placing each pilot sample at approximately the same circumferential location outside of the outer periphery of the pile as where the particular pilot sample was taken;
performing a first evaluation of the number of non-glass objects larger than a predetermined size in at least some of the pilot samples;
mixing the pilot samples;
distributing the mixed pilot samples onto a surface;
dividing the distributed pilot samples into a plurality of substantially equally sized sectors; and
performing a second evaluation on the sample material within one of the sectors of one of cullet color, organic contamination, or cullet size.
2. The method of claim 1 wherein said mixing is after said performing a first evaluation.
3. The method of claim 1 wherein the pile has a top and a bottom and said taking a pilot sample is from a height about midway from the bottom to the top.
4. The method of claim 1 wherein the predetermined circumferential locations are about equidistant from one another.
5. The method of claim 1 wherein each said sample is of approximately the same volume.
6. The method of claim 5 wherein said providing includes a scoop and said taking a pilot sample is with the same scoop.
7. The method of claim 1 wherein the evaluation of cullet size is to devalue sizes smaller than a predetermined size.
8. The method of claim 7 wherein the predetermined cullet size is about one-fourth inch.
9. The method of claim 1 wherein the evaluation of cullet size is to devalue sizes larger than a predetermined size.
10. The method of claim 9 wherein the predetermined cullet size is greater than about 2 inches.
11. The method of claim 1 wherein said performing a first evaluation is after said placing.