From Chunky Rock to Powder That Can Build a Palace
Ever looked at a plaster wall and thought
“Wow
This was once a giant rock?”
No?
Just me then
Well
You’re about to
Because gypsum goes on a wild ride before it ever ends up in your home
Or in your flower bed
Or in that ceiling that your mate Dave accidentally punched during charades
Let’s break it down
Step by step
With all the drama of a soap opera
And just a bit more dust
Step 1: Gypsum Mining
Where it all begins… in the dirt
So first up
We go rock hunting
Not the Instagram kind
The sweaty kind
Gypsum lives in sedimentary rock
And we grab it using either:
Open pit mining
Think digging a big hole
The kind a toddler with a spoon would dream of
Underground mining
Because some gypsum likes to play hard to get
Big machines like bulldozers and excavators do all the heavy lifting
Meanwhile the gypsum just lies there like
“Come get me”
Step 2: Crushing and Screening
Break it down like a 90s boy band
Now we’ve got massive rocks
Too big to do anything useful with
So we crush them
Crushers = big mechanical jaws
Not as scary as your ex
But close
Then we screen the pieces
Like a nightclub bouncer checking ID
“You’re too chunky mate
You’re not getting in”
What’s left is neat
Tidy
And ready for the next phase
Step 3: Drying
If your gypsum is soggy
You’ve got a problem
Some gypsum comes out all moist and clingy
We don’t want that
Especially not if it’s going into plasterboard
So
We pop it into a rotary kiln or industrial dryer
Basically a giant tumble dryer
But way more aggressive
Bye bye water
Hello dry dusty goodness
Step 4: Grinding
Time to powder this baby up
Dry gypsum gets ground down
And I mean properly ground down
Until it’s smoother than a jazz sax solo
Machines used:
Ball mills
Raymond mills
Hammer mills (not related to MC Hammer
sadly)
This is where you get gypsum powder
Also known as land plaster
Also known as fairy dust for the construction world
Step 5: Calcination
Science time
But we’ll keep it fun
Now we heat it
To around 150 to 160°C
Not hot enough to cook pizza
But hot enough to change its molecular vibe
It turns from CaSO₄·2H₂O (gypsum)
Into CaSO₄·½H₂O (plaster of Paris)
Yes
The same stuff your school used to make weird masks that smelled like feet
What we’re doing here is driving off some water
Like your mate driving off after you mention helping you move house
Step 6: Additives and Mixing
A bit of spice
For personality
Some gypsum gets special treatment
We chuck in additives like:
Retarders
Accelerators
Hardening agents
Why?
So it sets faster
Slower
Or stronger
Depending on the job
Like that one friend who can act calm
Until karaoke starts
Step 7: Shaping and Packaging
Time to get dressed and go out
Depending on what it’s going to be used for
The gypsum either:
Gets packed as powder
Turned into boards
Molded into ceiling roses that look fancy but no one ever cleans
Machines do all the packaging
Humans just press buttons and look dramatic with clipboards
Step 8: Quality Control
Because nobody wants dodgy plaster
Everything gets tested
Like a kid facing their GCSEs
They check:
Purity
Moisture
Particle size
Setting time
Strength
Bad batches get kicked to the kerb
Good ones get wrapped and sent off to build something brilliant
Real Talk
Gypsum’s glow up is serious
It starts as a rock
Ends up as a ceiling
Or a wall
Or helping plants grow in your nan’s garden
Every step matters
Because sloppy processing = bad builds
And bad builds = walls that crumble when you sneeze too hard
So if you’re using gypsum in any way
Know that there’s a whole soap opera happening behind the scenes
Now go forth and appreciate your walls
Like never before
FAQs About How Gypsum Is Processed
What is the main purpose of calcination in gypsum processing?
To remove water and turn raw gypsum into plaster of Paris
It’s the glow up stage
Why is drying necessary before grinding gypsum?
Because grinding soggy gypsum is like trying to chop soup
It does not work
Can gypsum be recycled?
Yes
Used gypsum boards can be ground and reused
Just like leftover pizza dough
But dustier
What’s the difference between gypsum and plaster of Paris?
Gypsum is the raw material
Plaster of Paris is what you get after calcination
Think of it as gypsum’s party outfit
Why do we add chemicals to gypsum powder?
To make it behave
Faster setting
Longer working time
More strength
Basically chemical parenting
Final Thoughts
Gypsum is more than just white powder
It’s a quiet hero
Holding up your house
Helping your tomatoes
And keeping builders everywhere sane
Next time you see a plaster wall
Just whisper
“Thanks rock buddy”
Now that’s some serious respect for the process
From raw gypsum
To something solid