SU1047944A1 - Method of producing polish powder - Google Patents

Abstract

A method for producing a polishing powder by heat treating a mixture of carbonates of rare earth elements, characterized in that, in order to increase the polishing ability of the powder and reduce its consumption, the following mixture of carbonates of rare earth elements is introduced: -18 . (L

Description

four;

4j

4 4

The invention relates to the mechanical processing of non-metallic materials, namely, polymeric powders, used for glass processing.

It is known that for polishing glass in the optomechanical industry, oxides of rare-earth elements (REE) in the form of cerium dioxide or a mixture of REE oxides are used mainly (CeOj, NdjOj,. Polishing powder used for polishing glass, ceramics and other materials is produced under named Polyrite., The main material and quantitative composition of polyrite is the following, all% CeO 48-53 22-28; 13-17Pr 0 4-6, Method of industrial production of REE carbonates flJ.

Polirite polishing powder does not satisfy the quality of the optical-mechanical industry. In addition, it is necessary to increase the polishing ability of the powder when processing glass of various grades differing in chemical composition and mechanical properties, as well as to improve the quality of the cleanliness of the surface of polished glass parts.

The known method of improving the quality of polyrite by introducing before heat treatment a mixture of rare earth carbonates of silica Cz J.

The use of this method leads to an increase in the polishing ability of the powder when processing glasses of solid and medium hardness, however, it introduces additional operations of activating and dispersing the components before their heat treatment.

There is a method of improving the quality of polyrite by introducing before heat treatment a mixture of rare earth carbonates of alkali metal fluorides, which provides an increase in the polishing ability of the powder when polishing silicate glasses of hard and medium hardness SZ.

However, the quality is polished. the glass surface does not improve. There are considerable difficulties in the implementation of the uniform distribution of small additions of alkali metal fluorides (0.5-2.0 weight,%) in the volume of REE carbonates. An excess of the additive above the norm leads to an increase in the pH of the suspension, which adversely affects the work of the resin polisher.

The closest to the proposed technical essence and the achieved effect is a method of obtaining a polishing powder by heat treatment of a mixture of rare earth carbonates with boron oxide 4 J.

The polishing powder obtained in this way is not economical with by /

Lirovaniya and does not have sufficient polirukatsey ability.

The purpose of the invention is to increase the polishing ability of nopouma and reduce its consumption.

The goal is achieved by the fact that in a known method of obtaining a polishing powder by heat treatment of a mixture of carbonates of rare-earth elements, bifluoride-ammonium is preliminarily introduced at a mass ratio of a mixture of carbonates of rare-earth elements and bifluoride-ammonium 82-92: 8-18.

Polishing powder was prepared as follows. /

Use a mixture of REE carbonates of the following composition, BJBC.%,). 52.0 Nd2 (COa) 3 16.0; La2 (CO), 26, S Pr2 (003) 3 5.5. In an aqueous suspension of a mixture of rare earth carbonates. (: 5) ammonium bifluoride is added in solid form in a given weight ratio. The mixture is stirred, and then the liquid phase is separated by centrifugation, the precipitate is dried at, then calcined in a muffle furnace for 1 hour.

Polishing powder is tested under conditions close to production when polishing flat optical parts with a diameter of 75 mm from glasses of the most common grades differing in chemical composition and mechanical properties (K 8, TF 5 BF 16). Glass of the K 8 grade is of medium hardness, relatively chemically stable, the glass of TF 5 and BF 16 are chemically unstable, and the glass of the brand, TF 5 is also one of the softest. Polishing is carried out using a manual sweep method on a BShP-200 g machine in the following modes: spindle rotation speed of 100 rpm, specific pressure of a polishing tool on glass 100 g / cm. The material of the polishing pad is peccanophilic resin. The concentration of the aqueous suspension of the powder, the suspension is fed to the polishing zone evenly after 30 seconds. The polishing ability of the powder is estimated by the amount of polished glass from the surface of the parts processed within 30 minutes. The surface quality of the polished part is evaluated by the class of purity according to GOST 11141-76.

Comparison of polishing properties of polishing powders obtained by the proposed method and prototype is carried out during their testing under the same conditions.

Table 1 shows the data on the polishing ability of the polisher (taken from the average of 4 measurements).

From tab. 1 it follows that the polishing powder obtained by the proposed method has a high

polishing ability when polishing onTiriecKHX of various glass grades (hard, medium hard, soft, chemically unstable), the total volume of production of which is not less than 95%, while improving the quality of the polished surface.

Compared to the prototype, the polishing capacity of polishing glass grades TF 5 is increased by 56%, BF 15 by 30%, K 8 is maintained.

In tab. Figure 2 presents comparative experimental data on the value of the polishing ability of powders when polishing glass K 8 with a reduced consumption of powder.

From the data table. 2 it follows that diluting the polishing slurry as compared with the accepted (T: W-1: 3) practically does not change 1.7 times, and 2.3 times insignificantly changes the polishing ability of the powder produced by the proposed method. At the same time, the quality of the surface of polished glass is preserved when the T: W ratio is changed. The polishing capacity of the prototype powder is reduced by 20 and 33%, respectively (at the optimum ratio of components). Similar to the polishing ability of T: W is observed in the case of polishing glass grades. TF 5 and BF 16.

Thus, high values

0 poliruktsyy ability of the powder made by the proposed method can be achieved at a lower flow rate (2 paiaa) compared to powder made by

S prototype.

The annual technical and economic effect, taking into account the reduction in polishing time, the consumption of powder Q and the increase in the yield of usable parts, by improving the quality of their surface, can be at least 800 thousand rubles. (on the optical-mechanical industry). Table 1

REE carbonates

Bifluoryl ammonium

REE carbonates

Ammonium bifluoride

REE carbonates

Ammonium bifluoride

REE carbonates

Ammonium bifluoride

REE carbonates

Ammonium bifluoride

REE carbonates

Boron oxide

REE carbonates

Boric oxide.

REE carbonates

Boron oxide

The proposed method

39 110 II-III and IV

II II III

127 94

II II III

156,100

137 95 II II-III III

41 108 80

III III III-IV

Prototype

97 70

III III IV

100 77

III 1II-IV IV

100 75

III IV IV

Continued table. one

Claims (1)

) METHOD FOR PRODUCING POLISHING ·! FOOT POWDER by heat treatment of a mixture of carbonates of rare-earth elements, (in order to increase the polishing ability of the powder and reduce its consumption, they are preliminarily introduced into the mixture of carbonates of rare-earth elements; bifluoridammonium at a mass ratio of the mixture of carbonates rare earths and bifluoridammonium 8292: 8-18.