Metal ores and the purification process

“Wherein ye greatly rejoice, though now for a season, if need be, ye are in heaviness through manifold temptations: that the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ.” 1 Peter 1:6-7

In the wise and always perfect way of God, manifold trials and tribulations have touched us in the past several months. Some have watched their parent or spouse suffer and/or die from cancer. Others have dealt with the loss of a child, either in death or waywardness. Congregations have even been touched with strife. And we all suffer either from the effect of the novel coronavirus (COVID-19) directly, or indirectly from the social and economic fallout of the governments’ responses to the pandemic. The Scriptures refer to such experiences as trials and tribulations, often using the example of purifying metal in a blazing hot furnace—a picture that was familiar to the people of that day— to teach us of the nature and goal of these trials. To help us appreciate the picture language in Scripture, we continue our examination of minerals through a short study of metal ores and their purification process.

Impure ores

Of the seven metals known to man prior to the Middle Ages, only gold was regularly found in its native form (unbonded to other substances). The other six metals (copper, lead, silver, tin, iron, and mercury) were found as mineral ores, that is, as bound to other elements. These elements are called “native elements”—the rare elements that may be found in the creation uncombined with other elements. However, they also can be found to some degree, bonded with other elements and thus will need to be purified in order to extract the pure metal. As we examined in our previous article (Nov. 15, 2019, p. 96) in this rubric, two large classifications of minerals are the Sulfides and the Oxides, of which the vast majority of our ores are composed. Common examples of these mineral ores are galena (lead sulfide), pyrite (iron sulfide), and bauxite (aluminum oxide), from which we extract our important raw metals of lead, iron, and aluminum for industrial purposes.

Obtaining pure native or raw metals is difficult be­cause the raw metals are permeated with impurities. It is first of all necessary to remove all rock debris and other minerals from the mineral ore. This debris, when removed, is called slag. Then the mineral ore itself must be purified to separate the desired native metal from the other elements that have bonded with it.

The reason a metallurgist desires to obtain the pure native metal, is that the pure metal is more valuable than the impure form. This is due to the fact that impurities present in the ore make for weak and brittle products. Besides this, the native metals are much more malleable (able to bend and shape) and ductile (able to stretch into wires) when in their pure form, making the pure form much more useful in casting molds of specific tools and implements.

One famous example of how impurities in a metal weaken products is worthy of note. Metallurgical stud­ies of the wreckage of the Titanic have revealed interest­ing information that may help explain, to some extent, why, from a scientific perspective, the “unsinkable” ship sank. Samples of rivets analyzed from the wreckage contained over 9% slag. Normal slag content in iron products is approximately 2%. Not only did these riv­ets contain a high level of impurity, but the slag was distributed within the metal in such a manner that it formed distinct lines of weakness. It is at these lines of weakness that the rivets sheared off when the Titanic side-swiped an iceberg. In addition, the ship’s steel hull contained a higher than typical level of sulfur. When exposed to frigid temperatures and violent impacts, steel with high levels of sulfur tends to experience “brit­tle fractures.” The side panels of the ship’s hull were, therefore, more easily gouged when it experienced the severe impact of hitting an iceberg.

The purification process

A likely contributing factor in the sinking of the Titanic was, therefore, the level of impurities in the metal ores from which those little rivets were made. Thus, the necessity of purification. The purification process of metal ores is often referred to as “smelting.” The technique of smelting ores has improved since those days when the Titanic was built. The techniques used today vary to some degree depending on the type of ore. As a rule, however, all smelting techniques have two things in common—intense heat and the addition of chemicals to aid in separating the pure metal from impurities.

In the case of metal carbonate ores and metal sul­fide ores, the first stage of the smelting process is called “roasting.” When the minerals are “roasted” they are heated intensely (1100o F) in the presence of oxy­gen. (For reference sake, paper ignites spontaneously at 451oF, while Earth’s magma is approximately 2000o F.) When the metal ores are heated so intensely, chem­ical bonds are broken and carbon dioxide gas or sulfur dioxide gas is released into the atmosphere, leaving behind a metal oxide compound (iron oxide, for example).

These remaining metal oxide compounds now enter the second stage of the smelting process called “reduc­tion.” The goal of this process is to remove the final oxygen atom from the native metal. This is accomplished by heating the metal oxide compound with charcoal (car­bon) in an air-starved furnace. With minimal oxygen (from the air) in the furnace, the oxygen atoms that are bonded to the metal atoms are stripped away from the metal. This process also requires extreme heat. Depend­ing on the ore being refined, the fiery furnace is heated to temperatures up to 2000o F. When this process is com­plete, a pure metal element, such as iron, remains.

The spiritual picture

The purification process of metal ores is used as a picture in Scripture to illustrate the fiery trials God wisely and sovereignly brings to His beloved children. For example, Scripture refers to these circumstances as “tribulations” (1 Thess. 3:4), which means “squeezed” or “put under intense pressure”—a concept in many ways very similar to the process of purifying ores.

In God’s just and perfect way for us we face “fiery trials” (1 Pet. 4:12)—poverty, cancer, a life-changing in­jury, a wayward child, church controversy, pestilence, war, or a sudden loss of a loved one, to name but a few. In the midst of these circumstances, we can experience such oppressive sorrow that we groan under the weight of it. The trials are manifold. The pain, agony, and in­tensity of them are real. We feel squeezed and scorched.

Yet, in God’s elect children, the gift of faith en­dures. Nothing endures by our own effort. Never! We are nothing but dross by nature. By nature we are nothing but wretched sinners. But God! Marvelous grace! “Gold perishes;….faith endures forever and ever, world without end.”1 As we, God’s elect children, pass through the furnace of affliction, we are stripped of all self-worth and earthly confidences. That which endures is faith. Nothing can scorch that which is genuine—the hope and joy we have by faith alone. With single-mind­ed devotion we cling to Christ and the promises of God to us in Him. We are reminded, in the midst of our fiery trials, of the sure and blessed hope that is ours in Christ alone—of our everlasting joy (1 Pet. 4:13). All honor, and glory, and thanks be to God!

This enduring of our faith, this demonstrating that our faith is genuine, is one of the purposes of God in send­ing us trials. The word “trial,” as in I Peter 1, has the meaning of “test,” “prove,” or “test the character.” Just as gold is tried (demonstrating its purity) in the smelting process, so our faith, in trials, is set forth as genuine. Only true and genuine faith finds joy and contentment where the eye of the body sees sorrow and suffering!! We stand in awe of God’s power to uphold, sustain, strength­en, and settle His people. This work of God’s grace—the amazing work of God’s Holy Spirit in our lives—is most beautiful and powerful! What a precious gift faith is! We rest in the certain knowledge of and hearty confi­dence in the goodness and wisdom of God’s ways!

In addition to demonstrating the genuineness of faith, God uses trials to strengthen our faith. When genuine faith “is put to the test, the result is that the believer is driven more closely to Christ, sinks his roots more deep­ly into Christ, flies more frequently to Christ for his ref­uge, and seeks from the work of his Savior the strength he needs to stand.”2 We are of the earth, earthy. We are busy in good earthly labors (raising children, working to provide for the family and the causes of the kingdom, etc.). The focus and goal in all our earthly life should be the glory of our God. But we can easily become distracted. At times, we readily seek earthly goods and pleasures more than those things that are pleasing to God. Throughout our lives, the Lord continuously re­focuses our attention on the reality that we are pilgrims and strangers on this earth. When we bite and devour each other, He promptly chastens us and leads us to care for each others’ needs. When we do not zealously love the truth or appreciate the manna or the portion He sends us, He suddenly takes it away. In the midst of our constant weakness and lack of faith, God wisely chas­tens us so that we cling more fervently to Christ. What a glorious and wise Father who constantly directs us away from sin and carnality and draws us unto Himself!

“Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby” (Heb. 12:11). Thanks be to God for the grace given to us that enables us to see our tri­als in their proper perspective. Thanks be to God for the gift of faith, by which we trust in God during such trying times, confidently knowing that He has a wise purpose in all that He sovereignly brings us in this life. How humbling to see our sinfulness and lack of faith and the need for such trials in our lives.

As we deal with the circumstances of life in 2020 and throughout the whole of our life, may the trials we face teach us to long more for our heavenly home. And may we see, in all the trials of this life, God’s faithfulness in working all these things for our good and the glory of His name.


1 Herman Hanko, A Pilgrim’s Manual: Commentary on I Peter (Jenison, MI: RFPA, 2012), 35

2 Hanko, A Pilgrim’s Manual, 34.