"Cherish and Protect Metal Resources" Metal PPT Courseware

"Cherish and Protect Metal Resources" Metal PPT Courseware

Why should metal resources be protected?

Reasons to protect metal resources:

⑴ A large amount of mining (hundreds of millions of tons) every year

⑵A large amount of metal is corroded every year (equivalent to 20%~40% of annual production)

1. Metal corrosion and protection

People have taken many measures, but the steel lost due to rust around the world every year accounts for about a quarter of the world's annual production!

The rusting process of iron

Under which conditions does iron rust most easily? Why?

a. In dry air

b. Immersed in water

c. Half submerged in water

Conditions for iron to rust:

Iron reacts chemically with oxygen and water vapor in the air.

4Fe+3O2+2XH2O=2Fe2O3 · XH2O (slow oxidation)

The composition of rust is very complex, mainly iron oxide Fe2O3·XH2O.

Conditions for iron products to rust:

⑴ There must be substances that can react (Fe, H2O, O2);

⑵The reactants must be able to contact each other;

⑶The products will not hinder the reaction.

(Fe2O3 · The reaction generates a dense Al2O3 film that covers the surface of aluminum, thus protecting the aluminum in the inner layer from reacting with oxygen, so aluminum is resistant to corrosion.)

Methods to prevent iron from rusting (just destroy the conditions for iron to rust):

1. Keep the surface of iron products clean and dry.

2. Apply oil, paint, enamel, plate corrosion-resistant metal, and bluing (that is, a dense oxide film protective layer is formed on the surface) on the surface of iron products to isolate the iron products from the air.

3. Make corrosion-resistant alloys, such as stainless steel, which are alloys made by adding a little nickel and chromium to steel.

2. How to protect metal resources?

⑴Prevent metal corrosion.

⑵Recycling and utilization of metals.

⑶ Minerals should be mined in a planned and reasonable manner, and random mining regardless of national interests is strictly prohibited.

⑷Look for metal substitutes. Such as replacing steel with plastic.

feedback exercise

1. Under the following circumstances, the cast iron pipes buried underground will corrode the fastest: ( )

A. In moist, dense soil

B. In dry, dense soil

C. In moist, loose soil

D. In dry, loose soil

2. When an iron ship is driven in water, the most rusty part is ( )

A. The bow part of the ship on the water

B. The part of the hull near the water surface

C. The bottom part of the ship under the water surface

D. All parts rust at the same rate

3. Some iron products in daily life are often rusted. Which of the following practices cannot prevent rust ( )

① Galvanize the surface of iron products

② Apply grease to the surface of iron products

③Retain the rust on the surface of iron parts as a protective layer

④Brush paint on the iron surface

⑤ Rinse the bicycle with clean water if it is dirty

⑥Use waste acid to flush iron sewage pipes

⑦After cutting the pickles, wash and dry the kitchen knife as soon as possible

A.②⑤B.③⑤⑥

C.①③⑦ D.②⑥⑦

1. Smelting iron ore into iron is a complex process. The main reaction principle is to use CO as a reducing agent under high temperature conditions to capture the oxygen in the iron ore and reduce the iron.

2. In actual production, the raw materials or products used generally contain impurities. When calculating materials and output, impurities should be taken into consideration.

3. The condition for iron to rust is that iron is in direct contact with oxygen and water (or water vapor) in the air. If the air and water are isolated, steel can be prevented from rusting to a certain extent. Oiling, painting, plating wear-resistant and corrosion-resistant chromium and making corrosion-resistant alloys, such as stainless steel, on the iron surface can prevent steel from rusting.

4. Effective ways to protect metal resources are to prevent metal corrosion, recycle and utilize scrap metal, mine minerals reasonably and effectively, and find metal substitutes.

Keywords: metal teaching courseware, cherishing and protecting metal resources teaching courseware, Guangdong Education Edition ninth grade chemistry PPT courseware download, second volume, ninth grade chemistry slide courseware download, metal PPT courseware download, cherishing and protecting metal resources PPT courseware download,. PPT format;

For more information about the PPT courseware "Metal Cherishing and Protecting Metal Resources", please click the Metal ppt Cherishing and Protecting Metal Resources ppt tab.

"Cherish and Protect Metal Resources" Metal PPT Courseware 4:

"Cherish and Protect Metal Resources" Metal PPT Courseware 4 1. Consumption of Metal Resources Information 1: Human beings require a large amount of metal mineral resources from nature every year to extract hundreds of millions of tons of metals. Metal minerals have limited reserves and are not renewable. According to the research...

"Cherish and Protect Metal Resources" Metal PPT Courseware 3:

"Cherish and Protect Metal Resources" Metal PPT Courseware 3 Consumption of Metal Resources Ask the question: Why does steel rust? Conjectures and assumptions: Chains and steel rings rust because of rain, carports and gates rust because they are exposed to the air for a long time, cars in factories...

"Cherish and Protect Metal Resources" Metal PPT Courseware 2:

"Cherish and Protect Metal Resources" Metal PPT Courseware 2 Learning Objectives 1. Know that metal resources on the earth are limited, and pay attention to the consumption of metal resources. 2. Understand the conditions for rust generation. 3. Understand several simple methods of rust prevention. 1. Our metal resources...