Gold: From Mining to Investment

Gold becomes a valuable asset after surviving a journey through industrial processes, but its value starts at the source, where it is found through mining, an intense and hard process with three different methods, each with its challenges.

Mining Methods

There are three main methods of mining: open pit mining, underground mining, and placer mining. Open pit mining is the oldest and cheapest form, but still poses risks to workers. Surface mining pits can collapse and disrupt local ecosystems, so mines often go deeper, using underground mining methods.

Open pit mining: the oldest and cheapest form, but poses risks to workers
Underground mining: involves two stages, development and production mining, and requires measures to secure the mines and prevent cave-ins
Placer mining: involves rinsing and sifting unconsolidated minerals mixed with sediments, and requires extensive surveying to determine the amount of recoverable gold

Underground Mining Process

Underground mining involves two stages: development, which removes unwanted rocks, and production mining, where the target resource is excavated. To ensure safety and efficiency, body examination is used to locate deposits, and measures like blowing crushed limestone dust on walls are taken to secure the mines and prevent cave-ins.

Miners use various equipment like rock dusters, roof bolters, and shotrete machines to prevent collapse and reinforce structural integrity. Drones and remotely controlled trucks, drills, and excavators also contribute to safer mining operations.

Gold Extraction and Refining

The extracted gold is usually 60-90% pure and requires further processing at a gold mill, where heat and chemicals are used to remove impurities. The process involves size reduction, such as grinding, to increase the surface area, and then various methods, including the use of cyanide, to refine the gold and separate it from other materials.

Gold is extracted from crushed ore using cyanide solution, a highly toxic chemical, or mechanical separation methods like centrifugal forces that utilize gravity and fluid dynamics to separate particles of different densities, and then refined to almost total purity through additional steps.

Refining Methods

There are several methods used to refine gold, including:

Electrolysis: uses an electrical current to refine gold, with hydrochloric acid as the electrolyte, and can achieve purity of 99.9% through the Woolwill process
Miller process: uses chlorine gas to refine gold, achieving slightly less purity, and is a method that utilizes a chemical reaction to purify the metal

Final Processing and Distribution

The gold is then melted at 1,947° F and poured into bars, requiring careful handling due to its extreme heat. After cooling, each bar is inspected for purity and a sample is taken for lab testing. If it meets standards, the bar is stamped with a serial number and certification mark, making it ready for distribution.

Gold Coins and Reserves

The US Mint produces gold coins that are legal tender under the Gold Bullion Coin Act of 1985, but the process is complex, involving buying gold bars, verifying purity and authenticity, melting and alloying to exact specifications, and shaping into coins.

The US has the largest gold reserve, worth $683.73 billion, held primarily at Fort Knox, the Denver Mint, and the West Point Bullion Depository, serving as a hedge against economic turbulence.

Gold as a Valued Commodity

Despite the rise of technology, gold remains a valued commodity, particularly as a hedge against inflation, and is stockpiled by governments. Something is valued not only for its beauty, but also for its industrial uses, making it a trusted investment. However, some believe cryptocurrency could replace gold as a store of value, but gold’s scarcity, physical presence, and heavy regulation give it an advantage over cryptocurrencies, which have been plagued by scams and volatility.

Key Vocabulary

Term	Definition	Example Usage
Open Pit Mining	A method of mining where minerals are extracted from a pit dug into the Earth’s surface.	Open pit mining is the oldest and cheapest form of mining, but poses risks to workers and the environment.
Underground Mining	A method of mining where minerals are extracted from beneath the Earth’s surface.	Underground mining involves two stages: development and production mining, and requires measures to secure the mines and prevent cave-ins.
Placer Mining	A method of mining where minerals are extracted from unconsolidated sediments, such as gravel or sand.	Placer mining involves rinsing and sifting unconsolidated minerals mixed with sediments, and requires extensive surveying to determine the amount of recoverable gold.
Gold Mill	A facility where gold is processed and refined to remove impurities.	The extracted gold is usually 60-90% pure and requires further processing at a gold mill, where heat and chemicals are used to remove impurities.
Cyanide Solution	A highly toxic chemical used to extract gold from crushed ore.	Gold is extracted from crushed ore using cyanide solution, a highly toxic chemical, or mechanical separation methods like centrifugal forces.
Electrolysis	A method of refining gold using an electrical current.	Electrolysis uses an electrical current to refine gold, with hydrochloric acid as the electrolyte, and can achieve purity of 99.9% through the Woolwill process.
Miller Process	A method of refining gold using chlorine gas.	The Miller process uses chlorine gas to refine gold, achieving slightly less purity, and is a method that utilizes a chemical reaction to purify the metal.
Gold Bullion Coin Act	A law that allows the US Mint to produce gold coins that are legal tender.	The US Mint produces gold coins that are legal tender under the Gold Bullion Coin Act of 1985, but the process is complex, involving buying gold bars, verifying purity and authenticity, melting and alloying to exact specifications, and shaping into coins.
Gold Reserve	A stockpile of gold held by a government or institution.	The US has the largest gold reserve, worth $683.73 billion, held primarily at Fort Knox, the Denver Mint, and the West Point Bullion Depository, serving as a hedge against economic turbulence.

Watch The Video

How 99% Pure Gold is Made – Inside Secret Gold Factory

Vocabulary Quiz

1. Which mining method involves rinsing and sifting unconsolidated minerals mixed with sediments?

A) Underground mining
B) Open pit mining
C) Placer mining
D) Surface mining

2. What is the purpose of blowing crushed limestone dust on walls in underground mining?

A) To locate deposits
B) To reinforce structural integrity and prevent cave-ins
C) To remove unwanted rocks
D) To excavate the target resource

3. What is the typical purity of extracted gold before further processing?

A) 90-99%
B) 60-90%
C) 40-60%
D) 99-100%

4. Which refining method uses an electrical current to refine gold?

A) Miller process
B) Electrolysis
C) Centrifugal forces
D) Cyanide solution

5. What is the main purpose of the US gold reserve, worth $683.73 billion?

A) To produce gold coins
B) To serve as a hedge against economic turbulence
C) To invest in cryptocurrency
D) To fund mining operations

Answer Key:

1. C
2. B
3. B
4. B
5. B

Grammar Focus

Grammar Focus: The Use of Gerunds and Infinitives

The use of gerunds and infinitives is a crucial aspect of English grammar, particularly for CEFR C1 level learners. Gerunds are verbs ending in -ing that function as nouns, while infinitives are verbs beginning with “to” that can function as nouns, adjectives, or adverbs. In the context of the provided text, gerunds and infinitives are used to describe processes and methods, such as “mining,” “extracting,” and “refining.” For example, “mining involves two stages” uses “mining” as a gerund, while “miners use equipment to prevent collapse” implies the infinitive “to prevent.” Understanding the correct use of gerunds and infinitives is essential for clear and effective communication, especially in technical and descriptive texts like the one provided.

Grammar Quiz:

Choose the correct form of the verb in parentheses to complete each sentence.

1. The process of gold extraction ____________________ (involve) several stages, including crushing and refining.

involves
to involve
involving
involved

2. The use of cyanide in gold refining ____________________ (be) a highly controversial method due to its toxicity.

is
being
to be
be

3. Miners ____________________ (use) specialized equipment to prevent cave-ins and ensure safety.

uses
to use
using
use

4. The gold refining process ____________________ (require) the use of high temperatures and chemicals.

requires
to require
requiring
required

5. The value of gold ____________________ (determine) by its purity and market demand.

is determined
determines
to determine
determining

Answer Key:

1. involves

2. is

3. use

4. requires

5. is determined