Study For Purifying Process Of High Pressure Diamond

It is very important to the industrial diamond production that the level of new purification process of synthetic diamonds is researched and developed. The purification process has a direct relation with the cost, the quality of the diamonds, and the environment influence. This paper summarized the conventional purification methods of synthetic diamonds, and pointed out their advantages and disadvantages. The new purification method is studied by experiments. Meanwhile, possible pollution may be caused during the production and the ways to prevention were explained in details. Profitable attempt is made to reclaim the waste byproducts. Both possibility of the reclaim of graphite and waste metal board and the techniques are confirmed. I. Introduction On The Procedure Of The Purification Of Synthetic Diamonds Synthetic diamond cell made by the way of static -pressure -catalyze is mainly made from diamond, Ni, Mo, Co, Fe and so on, and not-inverted graphite and pressure-transfer medium like leftover pyrophyllite etc. The separation method of synthetic diamond from cell is confirmed according to the abundant existence characteristic of synthetic diamond in the cell and its physical and chemical characteristic. In common, we use two methods to separate the diamond. The one is the physical separation. Conventional physical way like rocking-bed-separation and heavy-liquid-separation make use of the shape or density diversities of the materials. The advantage of this technique is easy and cheap, and no environment pollution. But it usually can't divide the mixture completely. The other is the chemical separation. This technique divides the mixture according to their chemistry characters. We solved the mixture with the acid, alkali or strong oxidant, and then the dissolved is diamond. This technique can separate the impurity completely, but have many shortcomings like using a lot of chemical reagents, bleeding off harmful waste liquids and gases. Hence, we replace the acid-treatment by electrolysis, in some extent, can get over the above shortcomings. Usually, the physical and chemical purification are combinatively used in industry. Ii. New Purification Of Synthetic Diamonds 1.New purification for piece catalyst cell We improved the conventional purification process and developed the new technique by adding the ball-milling process. It can drive the some graphite out, and the most of all the pyrophyllite. It not only accelerates the electrolysis, but also saves the cost of separatingthe pyrophyllite in conventional method. We can sift out the electrolysis products and make the rough electrolysis products reusing, and avoid using the acid. 2.New purification for powder catalyst cell Many techniques were tried. Finally we decide to break up the cell, then take the electrolysis, and make the post treatment. This technique can lower the cost and improve the working condition of employee, and higher the efficiency. So it has obvious benefit. III. Prevention & Cure to the Environment Pollution The main pollutions from the diamond purification are the heavy metal pollution and the gas pollution, which both can pollute the environment. This paper respectively introduced the disposal of Cl2, nitrogen oxide and waste water in details, and made a clean explanation of some waste scavenging system such as slant hole tower purification system, closed purification device, neutralization deposition device, waste water disposal system, and so on. IV. The Reclaim and Comprehensive Utilization of Outgrowth 1. Comprehensive utilization of the electrolysis alloy The chemical analysis show that the main elements of the waste panel are Ni and Co, especially the proportion of Co is 6%~8%. When we make catalyst with the waste Ni panel, we change the usual...