What are the industrial uses and consumption of silver?

In the electronic industry, the biggest use of silver is thick film paste, which is usually used to make screen printed circuits in multilayer ceramic capacitors, thin film switches, heating films for automobile rear windshields and conductive adhesives.

Silver has a unique light reflectivity, and the reflectivity after polishing reaches 100%, which can be used on mirrors, glass, cellophane or metal.

Many batteries, rechargeable batteries and disposable batteries use silver alloy as cathode. Although expensive, the energy of silver-containing batteries is better than other types of batteries. The most common is the button-sized silver oxide battery (containing 35% silver), which is usually used in watches, cameras and similar electronic products.

2. photography.

The photographic process is based on the photosensitivity of silver halide crystal, which consists of soluble silver solution, usually silver nitrate containing soluble alkali metal halide (such as sodium chloride or potassium bromide), and these particles are suspended in unexposed film.

The effect of light on silver halide destroyed the structure of this mixture. Under certain conditions, this mixture was reduced to metallic silver by the developer, and the image on the negative was converted into positive. Photographic film is used for X-ray photography, printing and commercial photography. Manufacturers of photographic films need high-purity silver.

3. Silver ornaments and silverware. The machinability of silver is similar to that of gold, both of which have good reflectivity and can reach high brightness after polishing. Pure silver (99.9%) does not lose its luster easily. In order to make jewelry have lasting luster, a small amount of copper is usually mixed into it. Silver is also used in gold alloys with base metals.

Since14th century, the standard pure silver with purity of 92.5% has been the standard for making silverware, especially for making "containers" and flat tableware (knives, forks, spoons, etc. ). The coating of electroplated silverware is usually 20 ~ 30 microns thick, and the gold-plated jewelry is only 3 ~ 5 microns.

Distinguish platinum

(1) Seal identification: Jewelry products should be marked with seals and their purity according to national standards. If the jewelry has the words "PT" or "PLATNUM" or "PLAT", it is platinum; If the word "S" or "SILVER" is on the jewelry, it is silver.

(2) Weighing: the specific gravity of platinum is 2 1.4, and that of silver is 10.49. Platinum with the same volume weighs twice as much as silver, so it can be distinguished by weighing it by hand.

(3) Comparison of appearance and hardness: When platinum is carefully observed by naked eyes, it will be slightly light gray and bright white, and its texture is hard. It is difficult to scratch the scar with a pin. Its Mohs hardness is 4.3, while silver is white, and its texture is smooth and delicate. Once oxidized, it will turn gray or black. Its Mohs hardness is 2.7, which is much softer than platinum.

Reference to the above content: Baidu Encyclopedia-Silver