CN1239156A

CN1239156A - Process for removing harmful rust from bronze articles with ammonia water and cyanide

Info

Publication number: CN1239156A
Application number: CN 98113596
Authority: CN
Inventors: 程昌炳
Original assignee: Wuhan Institute of Rock and Soil Mechanics of CAS
Current assignee: Wuhan Institute of Rock and Soil Mechanics of CAS
Priority date: 1998-06-12
Filing date: 1998-06-12
Publication date: 1999-12-22
Anticipated expiration: 2018-06-12
Also published as: CN1081248C

Abstract

A process for removing harmful rust of bronze articles features thatthe bronze article with rust is immersed in ammonia water and cyanide solution to remove the harmful CuCl. Its advantages include no damage to bronze article and no change in inherent lustre of bronze.

Description

Method for eliminating harmful patina of bronze ware by using ammonia water and cyanide

The present invention belongs to the field of cultural relics protecting technology.

Cultural relics bronze wares, which are affected by chemical environment due to being subjected to long-term underground burial, often contain CuCl, which is called harmful patina by cultural relic protection experts. After the bronze wares are excavated, so-called bronzing, in which further rusting of the bronze wares is caused by CuCl until the holes are perforated, often occurs, causing a great damage to the cultural relics.

The method for treating bronze disease commonly used by domestic and foreign cultural relic protection experts is basically to use Ag₂O-sealing and soaking in benzotriazole solution are available, but have certain limitations and do not completely solve the bronze problem. The main problem is that the original color of the bronze ware treated by the method is slightly changed, and although the bronze ware can be accepted by cultural relic protection temporarily, the bronze ware is a problem.

The invention aims to provide a method for eliminating harmful rust of bronze by using ammonia water and cyanide. In order to achieve the above object, the present invention for eliminating harmful patina in a bronze ware can be carried out in two steps, and the step of the present invention is to apply a pretreatment measure to the bronze ware to reduce the occurrence of bronzing, which has not been considered in the past. The pre-treatment method is to clean the copper ware which is not attacked, including the copper ware just emerged, to remove mud, and then to soak the copper ware in a container with ammonia water solution of any concentration, wherein the optimal concentration range is 3-15%. At room temperature. The time for soaking the container after the container is covered depends on the geometrical configuration complexity of the device, the structure is complex, and the longer the time is needed, the contact of the container and the ammonia water is difficult. The cork pieces are taken out from time to time during the soaking process to wipe off the dirt such as mud deposited on the surface of the utensil. And (3) fully leaching the soaked utensil with distilled water, soaking with the distilled water, replacing the distilled water for several times until the pH value of the soaking solution is 7.0, and finally taking out, air-drying and storing.

The second step of the invention is to treat bronze diseases of bronze wares after long-term storage. Soaking the bronze ware with cyanide solution of any concentration, the optimum concentration range of the cyanide solution is 3% -15%, the operation steps are also the same as those of the pretreatment, but the soaking times are the same as those of the pretreatment, and the solution does not contain Cl^-And then terminates.

Their chemical reaction is:

thus, the harmful CuCl which is a slightly soluble salt is changed into a soluble substance to be removed, and the root cause of the bronze disease is eliminated.

The method has the characteristics of simple operation, no need of special equipment, no damage to the background metal of the bronze ware and no change of the inherent color of the bronze ware.

Claims

1. A method for eliminating harmful patina of bronze ware is characterized in that the method uses ammonia water and cyanide solution to soak the bronze ware, and the specific method comprises the following steps:

① the bronze prevention device is made by soaking bronze ware in ammonia water solution of any concentration

The preferred concentration range is 3% -15%; the reaction formula is as follows:

② bronze ware has bronze disease, and is prepared by soaking bronze with cyanide solution of any concentration

The optimal concentration range is 3% -15%; the reaction formula is as follows:

③ placing bronze ware in the container containing the above chemical agent, and covering the container;

④ taking out bronze from time to time during soaking, and wiping off dirt on the surface of the tool with cork;

⑤ rinsing the bronze strip with distilled water, soaking, and replacing withdistilled water

When the bronze ware is soaked in ammonia water, the pH value of the soaking solution is 7.0; when leached with cyanide

Soaking until the soaking solution does not contain Cl^-Stopping, and air drying for storage.