Bench Blasting Application
I want to show an application from beginning to end in open pit bench blasting. Step-by-step we’re going to explain what we should do in an open pit bench blasting. In most of mine works which including open pit production methods use almost same stage in blasting. Of course, first stage is always blasting pattern design which were published before in MineBlog (see Open Pit Blasting Pattern Design Excel Sheet or cognito form). You can do that old-style pen-paper-calculator or you can use designing software specifically focused on blasting like DelPat etc. Or, you can use mine planning software like Surpac, Micromine, Vulcan or etc.
This application was made in an open pit chromite mine. Our parameters are as follows;
- Hole Diameter: 89 mm
- Bench Height: 5 m
- Pattern : Staggered
- Burden : 3,11 m
- Spacing: 3,89 m
- Stemming: 2,00 m
- Number of holes: 69
- Explosive charge per hole : 19,86 kg/hole
- Explosives: Dynamite + Heavy Anfo
- Pattern Design: Once you design your pattern you can always use that in your pit.
- Drilling: Drill the holes according to the pattern design.
- Fill the holes: Fill the holes with explosive material and then stemming with raw material (you can fill with material that extracted from hole by drilling machine). Do not forget to get a good stemming. Correct stemming will give you controlled and smooth blasting results.
- Connect the Handidets: you should connect them in a row like as follow
- First, you will connet the first row with handidets (we’ve used 25/500ms) from Hole 1 to Hole 2 and so on.
- Last step is that connetting rows each other with delay capsules (we’ve used 67ms). Important: You should connect the rows from second hole of each rows to first hole of next row. As you can see in the image below, second hole of first row connected to first hole of second row and, second hole of second row connected to first hole of third row.
- Fire in the Hole: fire the first hole of first row. When blasting is started, the sequence of blasting will be in following order: first, Hole 1 will be blasted then Hole 2, Hole 5 and so on like in image below.
So, you can see all aplication stages in image slider gallery on the top of post. When we finish all stages we can get an result as following video. This video captured from this blasting application.
See you soon.