Honey, I’ll put you on hold! BILL LANGER takes a moment away from his mineral-laden smartphone to explain how many fractions of minerals are present in the average unit and contribute to its functions.
Back in the mid-1980s my wife Pam and I were working with a realtor to look at houses. The fellow had a newfangled device called a mobile phone.
It was about the size of a shoebox, and had a handset like that on a traditional household phone of the time (if you can remember what that looked like). We were really impressed that he could call the office from his car.
Since that time mobile phones have evolved from simple communication devices into multi-function smartphones. As the phones became more complex, the list of elements needed to create them grew.
There were about 25 to 30 elements that went into the 1980s device. Today about 75 different elements (almost three-quarters of the periodic table) are needed to meet all the special functions of our smartphones.
Twelve of the elements in a smartphone, the amount of the element in the phone and their primary uses are shown in Table 1.
These elements are refined from minerals extracted all across the globe. You might wonder how much material is mined to make one smartphone.
Let’s start by looking at how much gold ore is mined to produce the 0.014 grams of gold used in a smartphone. For this exercise we will assume that a mine is capable of producing high grade ore, which is about eight to 10 grams of gold per tonne of ore (eight to 10 parts per million), and that the recovery of gold from processing the ore is 90 per cent.
First, there is no such thing as an average gold mine or average “any type of mine”. Similarly, the amount of gold or other metal recovered during processing also varies depending on the type of ore and the method of processing. So, the values I give above are very generalised.
The 0.014 grams of gold used in a smartphone is about the size of a grain of sand. The amount of high grade ore needed to obtain that amount of gold is about 1.6 kilograms. For lower grade ore the sample might be twice that size.
Of course, mining other elements can be much more efficient. For example, silica sand is used to make the screen of a smartphone. Most commercially worked silica sand deposits are at least 90 per cent pure, and very little of the material is lost during processing. So the tablespoon (15cm3 or so) of silica sand used in a smartphone might require mining a heaping tablespoon of sand.
Add to those two samples all the other types of ore that have to be mined to get the remaining 73 elements and you have a pile of rock that weighs somewhere around 34kg – just to make one 130g cell phone!
I gotta go! Pam just sent me a text message on my mineral-laden smartphone!