Start a Alum Making Business

  
(335). Start a Alum Making Business
Alum is a salt that in chemistry is a combination of an alkali metal, such as sodium, potassium, or ammonium and a trivalent metal, such as aluminum, iron, or chromium. The most common form, potassium aluminum sulfate, or potash alum, is one form that has been used in food processing. Another, sodium aluminum sulfate, is an ingredient in commercially produced baking powder.The potassium-based alum has been used to produce crisp cucumber and watermelon-rind pickles as well as maraschino cherries, where the aluminum ions strengthen the fruits' cell-wall pectins.
Its constituents are sulphuric acid, alumina, an alkali and water. The alkali may be either potash, soda, or ammonia. Hence there are three district species of slum, depending upon the nature of the alkali which each contains. Potash alum (in which the alkali is potash) is the common alum of this country, although both soda alum and ammoniacal alum are manufactured. The term alum is now used in chemistry as a generic one, and is applied to the class of double slats formed by the union of the sulphates of alumina, chromium, or iron with the sulphates of the alkalies. The composition of the ordinary potash alum is represented by the formula AIK(SO4)2 12H2O.


Alums are useful for a range of industrial processes. They are soluble in water; have an astringent, acid, and sweetish taste; react acidto litmus; and crystallize in regular octahedra. When heated they liquefy; and if the heating is continued, the water of crystallization is driven off, the salt froths and swells, and at last an amorphous powder remains.


Throughout history, people have been fascinated with crystals. Individuals have used them as beautiful jewelry pieces, in religious ceremonies, and even as healing objects and as energy sources. Crystals are created when molecules arrange themselves to form a repeated pattern, such as when material dissolves in a fluid and then solidifies. But just because there are chemical reactions involved in the process doesn't mean you can't grow your own colored crystal at home. While other crystals may require the use of a lab, alum crystals can be grown with common household items, plus alum powder, which is used in pickling recipes as a preservative.

How to grow Alum crystals:

1. Pour one half cup of boiling water into a clean jar and add alum to it until the solution is saturated and no more will dissolve.  This usually takes between two and three teaspoons of alum.
2. Let the jar rest undisturbed for a couple of hours, overnight is best.
3. You will notice that there are crystals in the bottom of the container now. Pour the liquid off into another clean jar, being careful not to get any solids into the new jar.
4. Choose the best crystal from the first jar and tie some string around it.
5. Suspend the crystal in the new jar, being careful not to let it touch any of the glass surfaces.  Make sure it is completely covered by the liquid.
6. Watch your crystal grow.  It will stop growing at some point, but you may remove it whenever you are satisfied with it. Let it dry.

How to grow Color Alum Crystal

Growing crystals at home was suprisingly easy to accomplish. To grow Alum crystals I had to purchase "Alum" at the grocery store in the spice isle. I then mixed the powder with warm water and let it sit overnight. In the morning you can see a substantial amount of crystals growing in the bottom of the cup. By using a bigger "seed" crystal and the rest of the alum mixture, you can let your crystal grow until it is the size you want. This photograph was taken of a 2 week old alum crystal and was shot using transilluminated polarized light. Polarized lighting was accomplished by placing the crystal between two matched polarized filters and rotating the filters to obtain the image most desired.

INSTRUCTIONS
Fill a glass jar 3/4 full with hot water. Pour alum into the jar while stirring the water. Add just enough alum to supersaturate the water, meaning the alum is no longer dissolving and instead begins to settle at the bottom.

Add enough drops of food coloring to the water to turn it a vibrant shade of that color. Then cover the jar loosely with a paper towel--this prevents dust from entering the jar--and allow the water to cool completely, preferably overnight.
Once the water has cooled completely, there should be small crystals at the bottom of the jar. Remove the largest and/or best-shaped crystal from the alum solution with a spoon and place it on a paper towel to dry completely. This will be the seed crystal from which a larger crystal will grow.

Pour the alum solution into a clean jar. Tie one end of a strand of nylon thread around the seed crystal, and tie the other end around the halfway point of a pencil. The thread should be as long as needed to complete the task in Step 5.

Lay the pencil across the top of the glass jar containing the alum solution so that the seed crystal is suspended in the water without touching the bottom or sides of the jar.

Cover the jar loosely with another paper towel to prevent dust from entering the jar, and allow the seed crystal to grow as large as desired over the next several days or weeks.

When small crystals begin to grow on the bottom or sides of the jar it means that too much alum in the water is contributing to the growth of those crystals instead of the growth of the seed crystal. Carefully remove the seed crystal, pour the solution into a clean jar and then carefully transfer the seed crystal to the clean jar.

Growing crystals is a slow and careful process because the crystals grow by adding single layers of molecules.  The crystal shape reflects the basic patterns by which the molecules of the crystal build up.

For example, growing a sugar crystal.  We start with a sugar solution which has as much sugar dissolve in it as possible.  As water evaporates, the sugar solution has too much sugar in it.  Sugar is forced to leave the water solution and become solid again.

Our mission is to coax this sugar to leave the water and go onto our baby (seed) crystal that we have suspended into the water solution.  Thus, as more water evaporates, our seed crystal grows and grows.  If this growth process is slow enough, our crystal will grow one layer at a time and and take on a interesting geometric shape: the crystal's shape reflects the directions of "slowest growth" of the crystal.

This recipe uses the evaporation process.  Water evaporates from a super-saturated solution of dissolved  material.  The process of growing a crystal can be broken down into the following steps:

• Making a saturated solution
  This is the bulked-up solution which, as water evaporates away, forms the crystal.
• Growing seed crystals
  "From tiny acorns, mighty oaks grow."  This saying goes for crystals, too.  Crystals will spontaneously grow from a saturated solution but, in order to control the process, you need to start with a seed.  As the saturated solution evaporates, crystal material deposits on the seed and not haphazardly everywhere else.
• Growing a crystal
  Crystal growing is like meditation.  A calm and steady environment produces healthy crystals.  Any variety of disturbances will lead to imperfection and discord.

Water is a safe and abundant solvent.  Anything that dissolves in water can potentially be used for crystal growth.  Some common materials that can be obtain at stores and pharmacies are:

• Sugar (sugar crystals are also called "rock candy")
• Salt (Sodium Chloride)
• Alum (usually aluminum ammonium sulphate)
• Copper Sulfate
• Rochelle Salt (Potassium Sodium Tartrate)
• Potassium Ferricyanide (don't let the cyanide part fool you.  It's a medicine.)

Some of these materials are not easy to use.  Some will creep up the side of the growth jar.  Others prefer to form clusters of crystals rather than single crystals.

For this exercise, we will be using common alum because it is easy to obtain, safe to use (it is a medical astringent), and produces clear tetrahedral-shaped crystals.  Also, putting a little chromium sulfate into the saturated solution adds a purple color to the crystals.

Remember the old Warner Bros. cartoons where Tweety Bird shoves a spoon of white powder into Sylvester the Cat's mouth.  Sylvester's mouth puckers up so much he can't eat Tweety Bird.  That powder is alum.

Pretty Crystal Pictures

Click on any of these thumbnails to see some of the home-grown crystals that can be made.

Potassium Ferricyanide	Copper Sulfate	Ammonium Alum (Co)	Alum Mixture	Rochelle Salt
small picture	small picture	small picture	small picture	small picture
large picture	large picture	large picture	large picture	large picture

Making a Saturated Solution

The first step in making crystals involves preparing a water solution that has as much alum dissolved in it as possible.  This is called a saturated solution.

1. Start with a clean jar that can be covered and shaken.  Add water to the jar.
    
2. Add an amount of alum to the water. Shake well and let stand for 30 minutes.
    
3. If there is NO powered alum visible on the bottom of the jar then repeat step 2 until there is.
    
4. Carefully pour off the liquid into another clean jar (without getting any powder into the liquid) and seal this new jar tightly.  This is your saturated solution.

  
 

Making Seed Crystals

Find a wide low jar.  Clean it well and pour some of the saturated solution into it.  Cover the low jar with a clean piece of cloth; this will allow the water to evaporate and keep dust from falling into the jar.

Set the jar in a dark area and wait.  Gradually, as the water evaporates, tiny crystals will begin to grow at the bottom of the jar.  Eventually, these crystals will be large enough to work with using your fingers.  Remove these "seed crystals" from the jar.  They will be used to make much larger crystals in the next step.

Sometimes, instead of getting a few seed crystals growing, you get a whole carpet of tiny crystals growing on the bottom of the jar.  This means either the water or the jar was dusty.

Growing Crystals

We are now ready to transform our tiny seeds into full blown crystals.

1. Clean a wide jar and place a wire over it as shown in the figure below.
   
2. Fill the jar with saturated solution.
   
3. Using thin nylon thread (or fishing line), tie a string to the seed crystal.  You may need to scratch some small grooves into the seed crystal for the string to hold onto the seed.  Avoid fabric threads since tiny seed crystals will form along the lint ends of the thread.  The result will be a gumble of crystals and not a single large crystal.
   
4. Suspend the seed crystal into the saturated solution close to the bottom of the jar.  Use a piece of tape to fix the string to the side of the jar.
   
5. Cover the top of the jar with clean cloth.  This keeps dust from falling into the jar and allows the water to evaporate out.

Finally, place the jar in a spot out of the sun where the temperature of the air does not change over time.  Gradually, over time, the water in the jar will evaporate.  Solid alum will leave the saturated solution and disposit onto the seed crystal.  The crystal will grow and change shape.  Because the crystal grows faster in some directions and slower in other directions, the crystal doesn't look round like a ball. The crystal's shape is determined by the directions that grow the slowest.

Final Comments and Other Links

There is no end to how large a crystal you can grow.  There is only an end to your patience.

These crystals were grown in a water solution.  Water is actually a part of these crystals: almost like a glue.  If you heat these crystals, the water would be forced out and the crystal would crumbled apart.

What would happen if you tried to grow a crystal in your refrigerator?

What would happen if you added water to the saturated solution while you were growing a crystal?